diff --git a/src/slic3r/GUI/GUI_ObjectManipulation.hpp b/src/slic3r/GUI/GUI_ObjectManipulation.hpp
index b926547421..a665764980 100644
--- a/src/slic3r/GUI/GUI_ObjectManipulation.hpp
+++ b/src/slic3r/GUI/GUI_ObjectManipulation.hpp
@@ -6,6 +6,7 @@
 #include "GUI_ObjectSettings.hpp"
 #include "GLCanvas3D.hpp"
 
+class wxBitmapComboBox;
 class wxStaticText;
 class LockButton;