diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenParameter.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenParameter.java
index 98770029381..c282fb519a2 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenParameter.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenParameter.java
@@ -122,7 +122,9 @@ public class CodegenParameter {
         if (this.items != null) {
             output.items = this.items;
         }
-        output.vendorExtensions = this.vendorExtensions;
+        if(this.vendorExtensions != null){
+            output.vendorExtensions = new HashMap<String, Object>(this.vendorExtensions);
+        }
         output.hasValidation = this.hasValidation;
         output.isBinary = this.isBinary;
         output.isByteArray = this.isByteArray;
diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenProperty.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenProperty.java
index b6a4b9d02da..66995f8d118 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenProperty.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenProperty.java
@@ -1,5 +1,7 @@
 package io.swagger.codegen;
 
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -283,9 +285,24 @@ public class CodegenProperty implements Cloneable {
     @Override
     public CodegenProperty clone() {
         try {
-            return (CodegenProperty) super.clone();
+        	CodegenProperty cp = (CodegenProperty) super.clone();
+        	if (this._enum != null) {
+                cp._enum = new ArrayList<String>(this._enum);
+            }
+            if (this.allowableValues != null) {
+                cp.allowableValues = new HashMap<String, Object>(this.allowableValues);
+            }
+            if (this.items != null) {
+                cp.items = this.items;
+            }
+        	if(this.vendorExtensions != null){
+                cp.vendorExtensions = new HashMap<String, Object>(this.vendorExtensions);
+            }
+        	return cp;
         } catch (CloneNotSupportedException e) {
             throw new IllegalStateException(e);
         }
     }
+    
+    
 }