diff --git a/src/msw/radiobox.cpp b/src/msw/radiobox.cpp
index 2d20f24418..54cd5c5a97 100644
--- a/src/msw/radiobox.cpp
+++ b/src/msw/radiobox.cpp
@@ -1025,6 +1025,8 @@ LRESULT APIENTRY _EXPORT wxRadioBtnWndProc(HWND hwnd,
                     }
                 }
             }
+            break;
+
 #ifdef __WIN32__
         case WM_HELP:
         {