diff --git a/Angle.h b/Angle.h
index 1cb2b8e..0c7db51 100644
--- a/Angle.h
+++ b/Angle.h
@@ -18,7 +18,7 @@ public:
 
   static AngleOf<T> pi;
 
-  bool AngleOf<T>::operator==(AngleOf<T> a);
+  bool operator==(AngleOf<T> a);
 
   static AngleOf<T> Normalize(AngleOf<T> a);
   static AngleOf<T> Clamp(AngleOf<T> a, AngleOf<T> min, AngleOf<T> max);