diff --git a/native_mate/converter.cc b/native_mate/converter.cc
index e5e7c52467..cc66b8d390 100644
--- a/native_mate/converter.cc
+++ b/native_mate/converter.cc
@@ -31,6 +31,20 @@ bool Converter<bool>::FromV8(Isolate* isolate, Handle<Value> val, bool* out) {
   return true;
 }
 
+Handle<Value> Converter<unsigned long>::ToV8(Isolate* isolate,
+                                             unsigned long val) {
+  return MATE_INTEGER_NEW(isolate, val);
+}
+
+bool Converter<unsigned long>::FromV8(Isolate* isolate, Handle<Value> val,
+                                      unsigned long* out) {
+  if (!val->IsNumber())
+    return false;
+  *out = val->IntegerValue();
+  return true;
+}
+
+
 Handle<Value> Converter<int32_t>::ToV8(Isolate* isolate, int32_t val) {
   return MATE_INTEGER_NEW(isolate, val);
 }
diff --git a/native_mate/converter.h b/native_mate/converter.h
index 86a1cc4cd0..37d86f82bf 100644
--- a/native_mate/converter.h
+++ b/native_mate/converter.h
@@ -33,6 +33,15 @@ struct Converter<bool> {
                      bool* out);
 };
 
+template<>
+struct Converter<unsigned long> {
+  static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
+                                    unsigned long val);
+  static bool FromV8(v8::Isolate* isolate,
+                     v8::Handle<v8::Value> val,
+                     unsigned long* out);
+};
+
 template<>
 struct Converter<int32_t> {
   static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,