diff --git a/Lib/javascript/v8/javascriptcode.swg b/Lib/javascript/v8/javascriptcode.swg
index 6ca0fff42..a6cd18c62 100644
--- a/Lib/javascript/v8/javascriptcode.swg
+++ b/Lib/javascript/v8/javascriptcode.swg
@@ -261,7 +261,7 @@ fail:
 %fragment("jsv8_define_class_template", "templates") 
 %{
   v8::Handle<v8::FunctionTemplate> $jsmangledname_class = SWIGV8_CreateClassTemplate("$jsmangledname");
-  $jsmangledname_clientData.class_templ = $jsmangledname_class;
+  $jsmangledname_clientData.class_templ.Reset(v8::Isolate::GetCurrent(), $jsmangledname_class);
   $jsmangledname_clientData.dtor = $jsdtor;  
   SWIGTYPE$jsmangledtype->clientdata = &$jsmangledname_clientData;
 %}
diff --git a/Lib/javascript/v8/javascriptruntime.swg b/Lib/javascript/v8/javascriptruntime.swg
index d23efcb55..12c274ed2 100644
--- a/Lib/javascript/v8/javascriptruntime.swg
+++ b/Lib/javascript/v8/javascriptruntime.swg
@@ -86,7 +86,7 @@ public:
 
 class SWIGV8_ClientData {
 public:
-  v8::Handle<v8::FunctionTemplate> class_templ;
+  v8::Persistent<v8::FunctionTemplate> class_templ;
   void (*dtor) (v8::Isolate *iso, v8::Persistent< v8::Object > *object, SWIGV8_Proxy *parameter);
 };