diff --git a/modules/swagger-codegen/src/main/java/com/wordnik/swagger/codegen/DefaultCodegen.java b/modules/swagger-codegen/src/main/java/com/wordnik/swagger/codegen/DefaultCodegen.java
index 062bcb5fe26..e84b85088ec 100644
--- a/modules/swagger-codegen/src/main/java/com/wordnik/swagger/codegen/DefaultCodegen.java
+++ b/modules/swagger-codegen/src/main/java/com/wordnik/swagger/codegen/DefaultCodegen.java
@@ -465,7 +465,7 @@ public class DefaultCodegen {
               System.out.println("failed to process model " + name);
               throw new RuntimeException(e);
             }
-            cp.required = false;
+            cp.required = null;
             if(impl.getRequired() != null) {
               for(String req : impl.getRequired()) {
                 if(key.equals(req))
@@ -879,7 +879,8 @@ public class DefaultCodegen {
     CodegenParameter p = CodegenModelFactory.newInstance(CodegenModelType.PARAMETER);
     p.baseName = param.getName();
     p.description = param.getDescription();
-    p.required = param.getRequired();
+    if(param.getRequired())
+      p.required = param.getRequired();
     p.jsonSchema = Json.pretty(param);
 
     if(param instanceof SerializableParameter) {
diff --git a/modules/swagger-codegen/src/test/scala/CodegenTest.scala b/modules/swagger-codegen/src/test/scala/CodegenTest.scala
index 3c31c87b25d..9e2a1d9fa9e 100644
--- a/modules/swagger-codegen/src/test/scala/CodegenTest.scala
+++ b/modules/swagger-codegen/src/test/scala/CodegenTest.scala
@@ -40,7 +40,7 @@ class CodegenTest extends FlatSpec with Matchers {
     val file = formParams.get(1)
     file.isFormParam should equal (true)
     file.dataType should be ("file")
-    file.required should equal (false)
+    file.required should equal (null)
     file.isFile should equal (true)
     file.hasMore should be (null)
   }
@@ -84,14 +84,14 @@ class CodegenTest extends FlatSpec with Matchers {
     nameParam.isFormParam should equal (true)
     nameParam.notFile should equal (true)
     nameParam.dataType should be ("String")
-    nameParam.required should equal (false)
+    nameParam.required should equal (null)
     nameParam.hasMore should equal (true)
 
     val statusParam = formParams.get(1)
     statusParam.isFormParam should equal (true)
     statusParam.notFile should equal (true)
     statusParam.dataType should be ("String")
-    statusParam.required should equal (false)    
+    statusParam.required should equal (null)    
     statusParam.hasMore should be (null)    
   }
 
diff --git a/modules/swagger-codegen/src/test/scala/Java/JavaModelTest.scala b/modules/swagger-codegen/src/test/scala/Java/JavaModelTest.scala
index 16fd6677a45..f5b26bf78e8 100644
--- a/modules/swagger-codegen/src/test/scala/Java/JavaModelTest.scala
+++ b/modules/swagger-codegen/src/test/scala/Java/JavaModelTest.scala
@@ -62,7 +62,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(2).defaultValue should be ("null")
     vars.get(2).baseType should be ("Date")
     vars.get(2).hasMore should equal (null)
-    vars.get(2).required should equal (false)
+    vars.get(2).required should equal (null)
     vars.get(2).isNotContainer should equal (true)
   }
 
@@ -91,7 +91,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(1).defaultValue should be ("new ArrayList<String>() ")
     vars.get(1).baseType should be ("List")
     vars.get(1).containerType should be ("array")
-    vars.get(1).required should equal (false)
+    vars.get(1).required should equal (null)
     vars.get(1).isContainer should equal (true)
   }
 
@@ -119,7 +119,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new HashMap<String, String>() ")
     vars.get(0).baseType should be ("Map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -150,7 +150,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new HashMap<String, List<Pet>>() ")
     vars.get(0).baseType should be ("Map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -175,7 +175,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).defaultValue should be ("null")
     vars.get(0).baseType should be ("Children")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isNotContainer should equal (true)
   }
 
@@ -203,7 +203,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new ArrayList<Children>() ")
     vars.get(0).baseType should be ("List")
     vars.get(0).containerType should be ("array")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -232,7 +232,7 @@ class JavaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new HashMap<String, Children>() ")
     vars.get(0).baseType should be ("Map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isNotContainer should be (null)
   }
diff --git a/modules/swagger-codegen/src/test/scala/Objc/ObjcModelTest.scala b/modules/swagger-codegen/src/test/scala/Objc/ObjcModelTest.scala
index 069b4a8e359..6255c4deacc 100644
--- a/modules/swagger-codegen/src/test/scala/Objc/ObjcModelTest.scala
+++ b/modules/swagger-codegen/src/test/scala/Objc/ObjcModelTest.scala
@@ -61,7 +61,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(2).defaultValue should be (null)
     vars.get(2).baseType should be ("NSDate")
     vars.get(2).hasMore should equal (null)
-    vars.get(2).required should equal (false)
+    vars.get(2).required should equal (null)
     vars.get(2).isNotContainer should equal (true)
 
   }
@@ -100,7 +100,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(1).baseType should be ("NSArray")
     vars.get(1).hasMore should be (null)
     vars.get(1).containerType should equal ("array")
-    vars.get(1).required should equal (false)
+    vars.get(1).required should equal (null)
     vars.get(1).isPrimitiveType should equal (true)
     vars.get(1).isContainer should equal (true)
   }
@@ -126,7 +126,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("translations")
     vars.get(0).baseType should be ("NSDictionary")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isPrimitiveType should equal (true)
   }
@@ -149,7 +149,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(0).datatype should be ("SWGChildren*")
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("SWGChildren")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isNotContainer should equal (true)
   }
 
@@ -174,7 +174,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("NSArray")
     vars.get(0).containerType should be ("array")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -200,7 +200,7 @@ class ObjcModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("NSDictionary")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isNotContainer should be (null)
   }
diff --git a/modules/swagger-codegen/src/test/scala/php/PhpModelTest.scala b/modules/swagger-codegen/src/test/scala/php/PhpModelTest.scala
index c3acaf15227..ffb1e59c85d 100644
--- a/modules/swagger-codegen/src/test/scala/php/PhpModelTest.scala
+++ b/modules/swagger-codegen/src/test/scala/php/PhpModelTest.scala
@@ -62,7 +62,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(2).defaultValue should be ("null")
     vars.get(2).baseType should be ("DateTime")
     vars.get(2).hasMore should equal (null)
-    vars.get(2).required should equal (false)
+    vars.get(2).required should equal (null)
     vars.get(2).isNotContainer should equal (true)
 
     cm.imports.size() should be (0)
@@ -101,7 +101,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(1).baseType should be ("array")
     vars.get(1).hasMore should be (null)
     vars.get(1).containerType should equal ("array")
-    vars.get(1).required should equal (false)
+    vars.get(1).required should equal (null)
     vars.get(1).isPrimitiveType should equal (true)
     vars.get(1).isContainer should equal (true)
   }
@@ -127,7 +127,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("translations")
     vars.get(0).baseType should be ("map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isPrimitiveType should equal (true)
   }
@@ -150,7 +150,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(0).datatype should be ("Children")
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("Children")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isNotContainer should equal (true)
   }
 
@@ -175,7 +175,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("array")
     vars.get(0).containerType should be ("array")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -201,7 +201,7 @@ class PhpModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).baseType should be ("map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isNotContainer should be (null)
   }
diff --git a/modules/swagger-codegen/src/test/scala/scala/ScalaModelTest.scala b/modules/swagger-codegen/src/test/scala/scala/ScalaModelTest.scala
index 0c71983b1d5..090e4cd5ffe 100644
--- a/modules/swagger-codegen/src/test/scala/scala/ScalaModelTest.scala
+++ b/modules/swagger-codegen/src/test/scala/scala/ScalaModelTest.scala
@@ -63,7 +63,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(2).defaultValue should be ("null")
     vars.get(2).baseType should be ("DateTime")
     vars.get(2).hasMore should equal (null)
-    vars.get(2).required should equal (false)
+    vars.get(2).required should equal (null)
     vars.get(2).isNotContainer should equal (true)
   }
 
@@ -91,7 +91,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(1).defaultValue should be ("new ListBuffer[String]() ")
     vars.get(1).baseType should be ("List")
     vars.get(1).containerType should be ("array")
-    vars.get(1).required should equal (false)
+    vars.get(1).required should equal (null)
     vars.get(1).isContainer should equal (true)
   }
 
@@ -119,7 +119,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new HashMap[String, String]() ")
     vars.get(0).baseType should be ("Map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -144,7 +144,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(0).name should be ("children")
     vars.get(0).defaultValue should be ("null")
     vars.get(0).baseType should be ("Children")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isNotContainer should equal (true)
   }
 
@@ -172,7 +172,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new ListBuffer[Children]() ")
     vars.get(0).baseType should be ("List")
     vars.get(0).containerType should be ("array")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
   }
 
@@ -201,7 +201,7 @@ class ScalaModelTest extends FlatSpec with Matchers {
     vars.get(0).defaultValue should be ("new HashMap[String, Children]() ")
     vars.get(0).baseType should be ("Map")
     vars.get(0).containerType should be ("map")
-    vars.get(0).required should equal (false)
+    vars.get(0).required should equal (null)
     vars.get(0).isContainer should equal (true)
     vars.get(0).isNotContainer should be (null)
   }