diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
index de6b8143c6b..093e3f5fd26 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
@@ -3333,7 +3333,7 @@ private void addVars(CodegenModel m, List<CodegenProperty> vars, Map<String, Pro
                     Model model =  allDefinitions.get(refProperty.getSimpleRef());
                     if (model instanceof ModelImpl) {
                         ModelImpl modelImpl = (ModelImpl) model;
-                        cp.pattern = modelImpl.getPattern();
+                        cp.pattern = toRegularExpression(modelImpl.getPattern());
                         cp.minLength = modelImpl.getMinLength();
                         cp.maxLength = modelImpl.getMaxLength();
                     }