diff --git a/src/modules/physics/box2d/World.h b/src/modules/physics/box2d/World.h
index 2c7eb78b7..9b8af3b89 100644
--- a/src/modules/physics/box2d/World.h
+++ b/src/modules/physics/box2d/World.h
@@ -42,6 +42,7 @@ namespace box2d
 
 class Contact;
 class Body;
+class Shape;
 class Joint;
 
 /**