diff --git a/index.js b/index.js
index c2b7581..c5b53f5 100644
--- a/index.js
+++ b/index.js
@@ -57,26 +57,38 @@ function parseCommand(cmd) {
     return parsedCommand;
 }
 
-function unparseOption(key, value, unparsed) {
+function unparseOption(key, value, unparsed, options) {
+    const delimiter = options.delimiter;
+    const useEqualSign = delimiter === '=';
+    const flaggedKey = keyToFlag(key);
+
     if (typeof value === 'string') {
-        unparsed.push(keyToFlag(key), value);
+        if (useEqualSign) {
+            unparsed.push(`${flaggedKey}=${value}`);
+        } else {
+            unparsed.push(flaggedKey, value);
+        }
     } else if (value === true) {
-        unparsed.push(keyToFlag(key));
+        unparsed.push(flaggedKey);
     } else if (value === false) {
         unparsed.push(`--no-${key}`);
     } else if (Array.isArray(value)) {
-        value.forEach((item) => unparseOption(key, item, unparsed));
+        value.forEach((item) => unparseOption(key, item, unparsed, options));
     } else if (isPlainObj(value)) {
         const flattened = flatten(value, { safe: true });
 
         for (const flattenedKey in flattened) {
             if (!isCamelCased(flattenedKey, flattened)) {
-                unparseOption(`${key}.${flattenedKey}`, flattened[flattenedKey], unparsed);
+                unparseOption(`${key}.${flattenedKey}`, flattened[flattenedKey], unparsed, options);
             }
         }
     // Fallback case (numbers and other types)
     } else if (value != null) {
-        unparsed.push(keyToFlag(key), `${value}`);
+        if (useEqualSign) {
+            unparsed.push(`${flaggedKey}=${value}`);
+        } else {
+            unparsed.push(flaggedKey, `${value}`);
+        }
     }
 }
 
@@ -130,7 +142,7 @@ function unparseOptions(argv, options, knownPositional, unparsed) {
             continue;
         }
 
-        unparseOption(key, argv[key], unparsed);
+        unparseOption(key, argv[key], unparsed, options);
     }
 }
 
diff --git a/test/index.spec.js b/test/index.spec.js
index a050d8e..ea0f38e 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -219,3 +219,26 @@ describe('interoperation with other libraries', () => {
         });
     });
 });
+
+describe('use equal mark as delimiter', () => {
+    it('should success', () => {
+        const argv = parse(['--no-cache', '--optimize', '--host', '0.0.0.0', '--collect', 'x', 'y', '--env', 'node', '--env', 'python'], {
+            boolean: ['cache', 'optimize'],
+            string: 'host',
+            array: ['collect', 'env'],
+        });
+        const argvArray = unparse(argv, {
+            delimiter: '=',
+        });
+
+        expect(argvArray).toEqual(['--no-cache', '--optimize', '--host=0.0.0.0', '--collect=x', '--collect=y', '--env=node', '--env=python']);
+
+        expect(minimist(argvArray)).toMatchObject({
+            cache: false,
+            optimize: true,
+            host: '0.0.0.0',
+            collect: ['x', 'y'],
+            env: ['node', 'python'],
+        });
+    });
+});