diff --git a/Lib/javascript/jsc/javascriptcode.swg b/Lib/javascript/jsc/javascriptcode.swg
index 3fe9d49e9..f8c5a200f 100644
--- a/Lib/javascript/jsc/javascriptcode.swg
+++ b/Lib/javascript/jsc/javascriptcode.swg
@@ -17,7 +17,7 @@ static JSObjectRef $jswrapper(JSContextRef context, JSObjectRef thisObject, size
     return SWIG_JSC_NewPointerObj(context, result, SWIGTYPE_$jsmangledtype, SWIG_POINTER_OWN);
     goto fail;
     fail:
-    return NULL;
+    return JSValueMakeUndefined(context);
 }
 %}
 
@@ -78,7 +78,7 @@ static JSObjectRef $jswrapper(JSContextRef context, JSObjectRef thisObject, size
 
     goto fail;
     fail:
-    return NULL;
+    return JSValueMakeUndefined(context);
 }
 %}
 
@@ -159,7 +159,7 @@ static JSValueRef $jswrapper(JSContextRef context, JSObjectRef thisObject, JSStr
 
     goto fail;
     fail:
-    return NULL;
+    return JSValueMakeUndefined(context);
 }
 %}
 
@@ -204,7 +204,7 @@ static JSValueRef $jswrapper(JSContextRef context, JSObjectRef function, JSObjec
 
   goto fail;
   fail:
-  return NULL;
+  return JSValueMakeUndefined(context);
 }
 %}
 
@@ -229,7 +229,7 @@ static JSValueRef $jswrapper(JSContextRef context, JSObjectRef function, JSObjec
 
   goto fail;
   fail:
-  return NULL;
+  return JSValueMakeUndefined(context);
 }
 %}