diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSimplify.hpp b/src/slic3r/GUI/Gizmos/GLGizmoSimplify.hpp
index b71aaffd56..a62721ff5d 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSimplify.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSimplify.hpp
@@ -40,7 +40,7 @@ protected:
     virtual void on_render() override;
     virtual void on_render_for_picking() override{};    
 
-    virtual CommonGizmosDataID on_get_requirements() const;
+    virtual CommonGizmosDataID on_get_requirements() const override;
 
 private:
     void apply_simplify();