diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/valibot/default/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/valibot/default/valibot.gen.ts
index 9a36fdf3f..62bacb938 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/valibot/default/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/valibot/default/valibot.gen.ts
@@ -703,10 +703,10 @@ export const vModelWithPattern = v.object({
     name: v.pipe(v.string(), v.maxLength(255)),
     enabled: v.optional(v.pipe(v.boolean(), v.readonly())),
     modified: v.optional(v.pipe(v.pipe(v.string(), v.isoTimestamp()), v.readonly())),
-    id: v.optional(v.pipe(v.string(), v.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: v.optional(v.pipe(v.string(), v.regex(/^\w+$/))),
-    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\nbbb/))),
+    id: v.optional(v.pipe(v.string(), v.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: v.optional(v.pipe(v.string(), v.regex(/^\\w+$/))),
+    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\\nbbb/))),
     patternWithBacktick: v.optional(v.pipe(v.string(), v.regex(/aaa`bbb/)))
 });
 
@@ -1093,10 +1093,10 @@ export const vModelWithPropertiesWritable = v.object({
 export const vModelWithPatternWritable = v.object({
     key: v.pipe(v.string(), v.maxLength(64), v.regex(/^[a-zA-Z0-9_]*$/)),
     name: v.pipe(v.string(), v.maxLength(255)),
-    id: v.optional(v.pipe(v.string(), v.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: v.optional(v.pipe(v.string(), v.regex(/^\w+$/))),
-    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\nbbb/))),
+    id: v.optional(v.pipe(v.string(), v.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: v.optional(v.pipe(v.string(), v.regex(/^\\w+$/))),
+    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\\nbbb/))),
     patternWithBacktick: v.optional(v.pipe(v.string(), v.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/validators/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/validators/valibot.gen.ts
index 9769db8fa..c79887e0e 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/validators/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/validators/valibot.gen.ts
@@ -10,7 +10,7 @@ export const vBar: v.GenericSchema = v.object({
 
 export const vFoo: v.GenericSchema = v.optional(v.union([
     v.object({
-        foo: v.optional(v.pipe(v.string(), v.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: v.optional(v.pipe(v.string(), v.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: v.optional(vBar),
         baz: v.optional(v.array(v.lazy(() => {
             return vFoo;
@@ -20,4 +20,4 @@ export const vFoo: v.GenericSchema = v.optional(v.union([
     v.null()
 ]), null);
 
-export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\nbar/)), v.readonly()), 'baz');
+export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\\nbar/)), v.readonly()), 'baz');
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/valibot/default/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/valibot/default/valibot.gen.ts
index 973798655..148058455 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/valibot/default/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/valibot/default/valibot.gen.ts
@@ -704,10 +704,10 @@ export const vModelWithPattern = v.object({
     name: v.pipe(v.string(), v.maxLength(255)),
     enabled: v.optional(v.pipe(v.boolean(), v.readonly())),
     modified: v.optional(v.pipe(v.pipe(v.string(), v.isoTimestamp()), v.readonly())),
-    id: v.optional(v.pipe(v.string(), v.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: v.optional(v.pipe(v.string(), v.regex(/^\w+$/))),
-    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\nbbb/))),
+    id: v.optional(v.pipe(v.string(), v.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: v.optional(v.pipe(v.string(), v.regex(/^\\w+$/))),
+    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\\nbbb/))),
     patternWithBacktick: v.optional(v.pipe(v.string(), v.regex(/aaa`bbb/)))
 });
 
@@ -1097,10 +1097,10 @@ export const vModelWithPropertiesWritable = v.object({
 export const vModelWithPatternWritable = v.object({
     key: v.pipe(v.string(), v.maxLength(64), v.regex(/^[a-zA-Z0-9_]*$/)),
     name: v.pipe(v.string(), v.maxLength(255)),
-    id: v.optional(v.pipe(v.string(), v.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: v.optional(v.pipe(v.string(), v.regex(/^\w+$/))),
-    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\nbbb/))),
+    id: v.optional(v.pipe(v.string(), v.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: v.optional(v.pipe(v.string(), v.regex(/^\\w+$/))),
+    patternWithSingleQuotes: v.optional(v.pipe(v.string(), v.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: v.optional(v.pipe(v.string(), v.regex(/aaa\\nbbb/))),
     patternWithBacktick: v.optional(v.pipe(v.string(), v.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-metadata/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-metadata/valibot.gen.ts
index c54dd93e8..7301f9fb0 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-metadata/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-metadata/valibot.gen.ts
@@ -18,7 +18,7 @@ export const vBar: v.GenericSchema = v.pipe(v.object({
  */
 export const vFoo: v.GenericSchema = v.optional(v.union([
     v.object({
-        foo: v.optional(v.pipe(v.pipe(v.string(), v.regex(/^\d{3}-\d{2}-\d{4}$/)), v.metadata({
+        foo: v.optional(v.pipe(v.pipe(v.string(), v.regex(/^\\d{3}-\\d{2}-\\d{4}$/)), v.metadata({
             description: 'This is foo property.'
         }))),
         bar: v.optional(vBar),
@@ -34,7 +34,7 @@ export const vFoo: v.GenericSchema = v.optional(v.union([
     v.null()
 ]), null);
 
-export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\nbar/)), v.readonly()), 'baz');
+export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\\nbar/)), v.readonly()), 'baz');
 
 export const vQux = v.record(v.string(), v.object({
     qux: v.optional(v.string())
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-types/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-types/valibot.gen.ts
index 3c12cbfaa..af1d594fb 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-types/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators-types/valibot.gen.ts
@@ -16,7 +16,7 @@ export const vBar: v.GenericSchema = v.object({
  */
 export const vFoo: v.GenericSchema = v.optional(v.union([
     v.object({
-        foo: v.optional(v.pipe(v.string(), v.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: v.optional(v.pipe(v.string(), v.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: v.optional(vBar),
         baz: v.optional(v.array(v.lazy(() => {
             return vFoo;
@@ -26,7 +26,7 @@ export const vFoo: v.GenericSchema = v.optional(v.union([
     v.null()
 ]), null);
 
-export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\nbar/)), v.readonly()), 'baz');
+export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\\nbar/)), v.readonly()), 'baz');
 
 export const vQux = v.record(v.string(), v.object({
     qux: v.optional(v.string())
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators/valibot.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators/valibot.gen.ts
index 3c12cbfaa..af1d594fb 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators/valibot.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/validators/valibot.gen.ts
@@ -16,7 +16,7 @@ export const vBar: v.GenericSchema = v.object({
  */
 export const vFoo: v.GenericSchema = v.optional(v.union([
     v.object({
-        foo: v.optional(v.pipe(v.string(), v.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: v.optional(v.pipe(v.string(), v.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: v.optional(vBar),
         baz: v.optional(v.array(v.lazy(() => {
             return vFoo;
@@ -26,7 +26,7 @@ export const vFoo: v.GenericSchema = v.optional(v.union([
     v.null()
 ]), null);
 
-export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\nbar/)), v.readonly()), 'baz');
+export const vBaz = v.optional(v.pipe(v.pipe(v.string(), v.regex(/foo\\nbar/)), v.readonly()), 'baz');
 
 export const vQux = v.record(v.string(), v.object({
     qux: v.optional(v.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts
index cbdcfbb53..b77dff897 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/default/zod.gen.ts
@@ -733,10 +733,10 @@ export const zModelWithPattern = z.object({
     name: z.string().check(z.maxLength(255)),
     enabled: z.optional(z.readonly(z.boolean())),
     modified: z.optional(z.readonly(z.iso.datetime())),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
@@ -1126,10 +1126,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().check(z.maxLength(64), z.regex(/^[a-zA-Z0-9_]*$/)),
     name: z.string().check(z.maxLength(255)),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/validators/zod.gen.ts
index a8be5f51c..7ec16b42b 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/mini/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar = z.object({
 
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -22,4 +22,4 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts
index 2d2a772a6..2f525bdc3 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/default/zod.gen.ts
@@ -731,10 +731,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.boolean().readonly().optional(),
     modified: z.string().datetime().readonly().optional(),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
@@ -1124,10 +1124,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/validators/zod.gen.ts
index a6537a847..6bd95fc8c 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v3/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar: z.AnyZodObject = z.object({
 
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -20,4 +20,4 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts
index aeb69d39e..47c37abf1 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/default/zod.gen.ts
@@ -733,10 +733,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.optional(z.boolean().readonly()),
     modified: z.optional(z.iso.datetime().readonly()),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
@@ -1126,10 +1126,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/validators/zod.gen.ts
index d0fb4e7a8..6459164a2 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.0.x/v4/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar = z.object({
 
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -22,4 +22,4 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts
index f45f4f952..54b62b13e 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/default/zod.gen.ts
@@ -740,10 +740,10 @@ export const zModelWithPattern = z.object({
     name: z.string().check(z.maxLength(255)),
     enabled: z.optional(z.readonly(z.boolean())),
     modified: z.optional(z.readonly(z.iso.datetime())),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
@@ -1132,10 +1132,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().check(z.maxLength(64), z.regex(/^[a-zA-Z0-9_]*$/)),
     name: z.string().check(z.maxLength(255)),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
index 3fd3ebc43..3c98dc531 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
index 1a5edf41c..a85cf11bc 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
@@ -18,7 +18,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/)).register(z.globalRegistry, {
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/)).register(z.globalRegistry, {
             description: 'This is foo property.'
         })),
         bar: z.optional(zBar),
@@ -36,7 +36,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
index a3170d6a4..248cb4fc7 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -32,7 +32,7 @@ export const zFoo = z._default(z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators/zod.gen.ts
index 5bcc24c6f..4daa0ecaf 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/mini/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts
index 2005c3692..529df7ec8 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/default/zod.gen.ts
@@ -738,10 +738,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.boolean().readonly().optional(),
     modified: z.string().datetime().readonly().optional(),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
@@ -1130,10 +1130,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
index 6eb670417..d8e8bcf22 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
index 585fddbb2..fae29bd68 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).describe('This is foo property.').optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).describe('This is foo property.').optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
index ace814995..6e4ce1bac 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -30,7 +30,7 @@ export const zFoo: z.ZodTypeAny = z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators/zod.gen.ts
index 83f84b2d0..10da0dc51 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v3/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts
index 2d383b3ed..e17eb792b 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/default/zod.gen.ts
@@ -740,10 +740,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.optional(z.boolean().readonly()),
     modified: z.optional(z.iso.datetime().readonly()),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
@@ -1132,10 +1132,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
index fa1234e0a..0d831e9ca 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
index 5e997ec27..0fed69910 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
@@ -18,7 +18,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/).register(z.globalRegistry, {
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).register(z.globalRegistry, {
             description: 'This is foo property.'
         })),
         bar: z.optional(zBar),
@@ -36,7 +36,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
index 2794c6a1e..2077751d4 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -32,7 +32,7 @@ export const zFoo = z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators/zod.gen.ts
index f9c56845a..60ad8519c 100644
--- a/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v3/__snapshots__/3.1.x/v4/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts
index 459ac09e6..48ad3c3e5 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/default/zod.gen.ts
@@ -733,10 +733,10 @@ export const zModelWithPattern = z.object({
     name: z.string().check(z.maxLength(255)),
     enabled: z.optional(z.readonly(z.boolean())),
     modified: z.optional(z.readonly(z.iso.datetime())),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
@@ -1126,10 +1126,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().check(z.maxLength(64), z.regex(/^[a-zA-Z0-9_]*$/)),
     name: z.string().check(z.maxLength(255)),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/validators/zod.gen.ts
index 77ab57f60..9988a8f22 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/mini/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar = z.object({
 
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -22,4 +22,4 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts
index 83a62aa1c..0224010e8 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/default/zod.gen.ts
@@ -731,10 +731,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.boolean().readonly().optional(),
     modified: z.string().datetime().readonly().optional(),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
@@ -1124,10 +1124,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/validators/zod.gen.ts
index 1b13ab9cb..1d7d2fee4 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v3/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar: z.AnyZodObject = z.object({
 
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -20,4 +20,4 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts
index 9fbb92dbe..147a56358 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/default/zod.gen.ts
@@ -733,10 +733,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.optional(z.boolean().readonly()),
     modified: z.optional(z.iso.datetime().readonly()),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
@@ -1126,10 +1126,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/validators/zod.gen.ts
index 7f3ce000b..2e6181f2f 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.0.x/v4/validators/zod.gen.ts
@@ -10,7 +10,7 @@ export const zBar = z.object({
 
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -22,4 +22,4 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts
index 14bef957d..8ffc81e4a 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/default/zod.gen.ts
@@ -740,10 +740,10 @@ export const zModelWithPattern = z.object({
     name: z.string().check(z.maxLength(255)),
     enabled: z.optional(z.readonly(z.boolean())),
     modified: z.optional(z.readonly(z.iso.datetime())),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
@@ -1132,10 +1132,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().check(z.maxLength(64), z.regex(/^[a-zA-Z0-9_]*$/)),
     name: z.string().check(z.maxLength(255)),
-    id: z.optional(z.string().check(z.regex(/^\d{2}-\d{3}-\d{4}$/))),
-    text: z.optional(z.string().check(z.regex(/^\w+$/))),
-    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9']*$/))),
-    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\nbbb/))),
+    id: z.optional(z.string().check(z.regex(/^\\d{2}-\\d{3}-\\d{4}$/))),
+    text: z.optional(z.string().check(z.regex(/^\\w+$/))),
+    patternWithSingleQuotes: z.optional(z.string().check(z.regex(/^[a-zA-Z0-9\']*$/))),
+    patternWithNewline: z.optional(z.string().check(z.regex(/aaa\\nbbb/))),
     patternWithBacktick: z.optional(z.string().check(z.regex(/aaa`bbb/)))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
index f5db2ce5c..635b40f8b 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
index 4b4759e2d..42c8b794a 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-metadata/zod.gen.ts
@@ -18,7 +18,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/)).register(z.globalRegistry, {
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/)).register(z.globalRegistry, {
             description: 'This is foo property.'
         })),
         bar: z.optional(zBar),
@@ -36,7 +36,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
index 1eb0cfb95..2458ff3b0 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -32,7 +32,7 @@ export const zFoo = z._default(z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators/zod.gen.ts
index 0ee090a1a..d9f8e3f87 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/mini/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z._default(z.union([
     z.object({
-        foo: z.optional(z.string().check(z.regex(/^\d{3}-\d{2}-\d{4}$/))),
+        foo: z.optional(z.string().check(z.regex(/^\\d{3}-\\d{2}-\\d{4}$/))),
         bar: z.optional(zBar),
         get baz(): z.ZodMiniOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z._default(z.union([
     z.null()
 ]), null);
 
-export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\nbar/))), 'baz');
+export const zBaz = z._default(z.readonly(z.string().check(z.regex(/foo\\nbar/))), 'baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts
index 8a9c58819..8eb1323e0 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/default/zod.gen.ts
@@ -738,10 +738,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.boolean().readonly().optional(),
     modified: z.string().datetime().readonly().optional(),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
@@ -1130,10 +1130,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.string().regex(/^\d{2}-\d{3}-\d{4}$/).optional(),
-    text: z.string().regex(/^\w+$/).optional(),
-    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9']*$/).optional(),
-    patternWithNewline: z.string().regex(/aaa\nbbb/).optional(),
+    id: z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/).optional(),
+    text: z.string().regex(/^\\w+$/).optional(),
+    patternWithSingleQuotes: z.string().regex(/^[a-zA-Z0-9\']*$/).optional(),
+    patternWithNewline: z.string().regex(/aaa\\nbbb/).optional(),
     patternWithBacktick: z.string().regex(/aaa`bbb/).optional()
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
index 140dc5e8c..84c0ef913 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
index efc9209a2..cb0253656 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-metadata/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).describe('This is foo property.').optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).describe('This is foo property.').optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
index 399d2c413..b82a47a38 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -30,7 +30,7 @@ export const zFoo: z.ZodTypeAny = z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators/zod.gen.ts
index fcc9c8c55..7eb4cfe7b 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v3/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar: z.AnyZodObject = z.object({
  */
 export const zFoo: z.ZodTypeAny = z.union([
     z.object({
-        foo: z.string().regex(/^\d{3}-\d{2}-\d{4}$/).optional(),
+        foo: z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).optional(),
         bar: zBar.optional(),
         baz: z.array(z.lazy(() => {
             return zFoo;
@@ -26,7 +26,7 @@ export const zFoo: z.ZodTypeAny = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.object({
     qux: z.string().optional()
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts
index 7ec52bfb3..71ffcb269 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/default/zod.gen.ts
@@ -740,10 +740,10 @@ export const zModelWithPattern = z.object({
     name: z.string().max(255),
     enabled: z.optional(z.boolean().readonly()),
     modified: z.optional(z.iso.datetime().readonly()),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
@@ -1132,10 +1132,10 @@ export const zModelWithPropertiesWritable = z.object({
 export const zModelWithPatternWritable = z.object({
     key: z.string().max(64).regex(/^[a-zA-Z0-9_]*$/),
     name: z.string().max(255),
-    id: z.optional(z.string().regex(/^\d{2}-\d{3}-\d{4}$/)),
-    text: z.optional(z.string().regex(/^\w+$/)),
-    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9']*$/)),
-    patternWithNewline: z.optional(z.string().regex(/aaa\nbbb/)),
+    id: z.optional(z.string().regex(/^\\d{2}-\\d{3}-\\d{4}$/)),
+    text: z.optional(z.string().regex(/^\\w+$/)),
+    patternWithSingleQuotes: z.optional(z.string().regex(/^[a-zA-Z0-9\']*$/)),
+    patternWithNewline: z.optional(z.string().regex(/aaa\\nbbb/)),
     patternWithBacktick: z.optional(z.string().regex(/aaa`bbb/))
 });
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
index 9b0132631..eafccda57 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-dates/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
index 34e6fe096..68df7a4ee 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-metadata/zod.gen.ts
@@ -18,7 +18,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/).register(z.globalRegistry, {
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/).register(z.globalRegistry, {
             description: 'This is foo property.'
         })),
         bar: z.optional(zBar),
@@ -36,7 +36,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
index 649cd0534..5caf5fdca 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators-types/zod.gen.ts
@@ -18,7 +18,7 @@ export type BarZodType = z.infer<typeof zBar>;
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -32,7 +32,7 @@ export const zFoo = z.union([
 
 export type FooZodType = z.infer<typeof zFoo>;
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export type BazZodType = z.infer<typeof zBaz>;
 
diff --git a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators/zod.gen.ts b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators/zod.gen.ts
index 921e41c46..ca9cd2834 100644
--- a/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators/zod.gen.ts
+++ b/packages/openapi-ts-tests/zod/v4/__snapshots__/3.1.x/v4/validators/zod.gen.ts
@@ -16,7 +16,7 @@ export const zBar = z.object({
  */
 export const zFoo = z.union([
     z.object({
-        foo: z.optional(z.string().regex(/^\d{3}-\d{2}-\d{4}$/)),
+        foo: z.optional(z.string().regex(/^\\d{3}-\\d{2}-\\d{4}$/)),
         bar: z.optional(zBar),
         get baz(): z.ZodOptional {
             return z.optional(z.array(z.lazy((): any => {
@@ -28,7 +28,7 @@ export const zFoo = z.union([
     z.null()
 ]).default(null);
 
-export const zBaz = z.string().regex(/foo\nbar/).readonly().default('baz');
+export const zBaz = z.string().regex(/foo\\nbar/).readonly().default('baz');
 
 export const zQux = z.record(z.string(), z.object({
     qux: z.optional(z.string())
diff --git a/packages/openapi-ts/src/openApi/3.0.x/parser/schema.ts b/packages/openapi-ts/src/openApi/3.0.x/parser/schema.ts
index b80ca1949..1ca3f8c5d 100644
--- a/packages/openapi-ts/src/openApi/3.0.x/parser/schema.ts
+++ b/packages/openapi-ts/src/openApi/3.0.x/parser/schema.ts
@@ -1,6 +1,7 @@
 import type { IR } from '../../../ir/types';
 import { addItemsToSchema } from '../../../ir/utils';
 import { refToName } from '../../../utils/ref';
+import { getPattern } from '../../common/parser/getPattern';
 import type {
   SchemaState,
   SchemaType,
@@ -98,7 +99,7 @@ const parseSchemaMeta = ({
   }
 
   if (schema.pattern) {
-    irSchema.pattern = schema.pattern;
+    irSchema.pattern = getPattern(schema.pattern);
   }
 
   if (schema.readOnly) {
diff --git a/packages/openapi-ts/src/openApi/3.1.x/parser/schema.ts b/packages/openapi-ts/src/openApi/3.1.x/parser/schema.ts
index b2ac1c3f7..40e42e575 100644
--- a/packages/openapi-ts/src/openApi/3.1.x/parser/schema.ts
+++ b/packages/openapi-ts/src/openApi/3.1.x/parser/schema.ts
@@ -1,6 +1,7 @@
 import type { IR } from '../../../ir/types';
 import { addItemsToSchema } from '../../../ir/utils';
 import { refToName } from '../../../utils/ref';
+import { getPattern } from '../../common/parser/getPattern';
 import type {
   SchemaState,
   SchemaType,
@@ -126,7 +127,7 @@ const parseSchemaMeta = ({
   }
 
   if (schema.pattern) {
-    irSchema.pattern = schema.pattern;
+    irSchema.pattern = getPattern(schema.pattern);
   }
 
   if (schema.readOnly) {
diff --git a/packages/openapi-ts/src/tsc/__tests__/types.test.ts b/packages/openapi-ts/src/tsc/__tests__/types.test.ts
index bd1c94a63..14c96123d 100644
--- a/packages/openapi-ts/src/tsc/__tests__/types.test.ts
+++ b/packages/openapi-ts/src/tsc/__tests__/types.test.ts
@@ -73,4 +73,27 @@ describe('createRegularExpressionLiteral', () => {
       '/^data:image\\/svg\\+xml;base64,[A-Za-z0-9+\\/]+=*$/',
     );
   });
+
+  it('should handle patterns with backslash followed by forward slash', () => {
+    // Pattern from getPattern() which has doubled backslashes: ^[^.][^\\/:*?"<>| ]*$
+    // This represents a character class that excludes: backslash, forward slash, colon, etc.
+    // The \\ in the input string represents a single backslash in the regex
+    const result = createRegularExpressionLiteral({
+      text: '^[^.][^\\\\/:*?"<>| ]*$',
+    });
+
+    // The output should have the backslashes preserved and the forward slash not escaped
+    // (because it's already preceded by a backslash)
+    expect(result.text).toBe('/^[^.][^\\\\/:*?"<>| ]*$/');
+  });
+
+  it('should handle patterns with multiple consecutive backslashes', () => {
+    // Input: ^\d{3}-\d{2}-\d{4}$ (with doubled backslashes from getPattern)
+    const result = createRegularExpressionLiteral({
+      text: '^\\\\d{3}-\\\\d{2}-\\\\d{4}$',
+    });
+
+    // Backslashes should be preserved as-is
+    expect(result.text).toBe('/^\\\\d{3}-\\\\d{2}-\\\\d{4}$/');
+  });
 });
diff --git a/packages/openapi-ts/src/tsc/types.ts b/packages/openapi-ts/src/tsc/types.ts
index af869048b..a214a488f 100644
--- a/packages/openapi-ts/src/tsc/types.ts
+++ b/packages/openapi-ts/src/tsc/types.ts
@@ -1084,8 +1084,27 @@ export const createRegularExpressionLiteral = ({
   const patternContent =
     text.startsWith('/') && text.endsWith('/') ? text.slice(1, -1) : text;
 
-  // Escape forward slashes in the pattern content, but only if they're not already escaped
-  const escapedPattern = patternContent.replace(/(?<!\\)\//g, '\\/');
+  // Escape forward slashes in the pattern content, but only if they're not preceded by a backslash.
+  // When getPattern() doubles backslashes, a sequence like \\ (two backslashes) followed by /
+  // means a literal backslash in the regex, followed by a forward slash. In a regex literal,
+  // this can be written as \\/ (no need to escape the / because it's after a backslash).
+  // However, a standalone / needs to be escaped as \/.
+  let escapedPattern = '';
+  for (let i = 0; i < patternContent.length; i++) {
+    const char = patternContent[i];
+    if (char === '/') {
+      // Check if there's a backslash immediately before this forward slash
+      if (i > 0 && patternContent[i - 1] === '\\') {
+        // Forward slash is preceded by a backslash, no need to escape
+        escapedPattern += '/';
+      } else {
+        // Forward slash needs escaping
+        escapedPattern += '\\/';
+      }
+    } else {
+      escapedPattern += char;
+    }
+  }
 
   // Wrap with forward slashes
   const textWithSlashes = `/${escapedPattern}/`;