1 files changed, 1 insertions, 1 deletions
diff --git a/Object.h b/Object.h
index 19a667c8..bcf2c481 100644
--- a/Object.h
+++ b/Object.h
@@ -46,7 +46,7 @@ extern ObjectClass Object_class;
 
 #ifdef DEBUG
 
-bool Object_isA(Object* o, const ObjectClass* klass);
+extern bool Object_isA(Object* o, const ObjectClass* klass);
 
 #endif