diff --git a/bindings/ruby/sfml-window/window/Window.cpp b/bindings/ruby/sfml-window/window/Window.cpp
index 043a7049f..d0c4ee2fa 100644
--- a/bindings/ruby/sfml-window/window/Window.cpp
+++ b/bindings/ruby/sfml-window/window/Window.cpp
@@ -33,12 +33,6 @@ extern VALUE globalEventClass;
 extern VALUE globalInputClass;
 extern VALUE globalVector2Class;
 
-#define VALIDATE_CLASS( variable, type, name ) \
-if( CLASS_OF( variable ) != type ) \
-{ \
-	rb_raise( rb_eTypeError, "%s argument must be instance of %s", name, rb_string_value_cstr ( &type ) ); \
-}
-
 /* Free a heap allocated object 
  * Not accessible trough ruby directly!
  */
diff --git a/bindings/ruby/sfml-window/window/main.hpp b/bindings/ruby/sfml-window/window/main.hpp
index f3e77023b..8be00af76 100644
--- a/bindings/ruby/sfml-window/window/main.hpp
+++ b/bindings/ruby/sfml-window/window/main.hpp
@@ -30,6 +30,12 @@ extern "C" void Init_window( void );
 
 typedef VALUE ( *RubyFunctionPtr )( ... );
 
+#define VALIDATE_CLASS( variable, type, name ) \
+if( rb_obj_is_kind_of( variable, type ) != Qtrue ) \
+{ \
+	rb_raise( rb_eTypeError, "%s argument must be instance of %s", name, rb_string_value_cstr ( &type ) ); \
+}
+
 #define rb_define_singleton_method( klass, name, func, argc, ... ) rb_define_singleton_method( klass, name, reinterpret_cast< RubyFunctionPtr >( func ), argc, ##__VA_ARGS__ )
 #define rb_define_method( klass, name, func, argc, ... ) rb_define_method( klass, name, reinterpret_cast< RubyFunctionPtr >( func ), argc, ##__VA_ARGS__ )