diff --git a/dll/win32/shell32/shellmenu/CMenuToolbars.cpp b/dll/win32/shell32/shellmenu/CMenuToolbars.cpp
index fd98086e4a2..aa3d4513433 100644
--- a/dll/win32/shell32/shellmenu/CMenuToolbars.cpp
+++ b/dll/win32/shell32/shellmenu/CMenuToolbars.cpp
@@ -261,6 +261,10 @@ HRESULT CMenuToolbarBase::OnCustomDraw(LPNMTBCUSTOMDRAW cdraw, LRESULT * theResu
         }
         *theResult = TRUE;
         return S_OK;
+
+    default:
+        *theResult = 0L;
+        break;
     }
     return S_OK;
 }