diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index 7c500f51e7..bc57847ca7 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -1228,8 +1228,12 @@ LRESULT WINAPI RichEditANSIWndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lP
     return 0;
   }
   case EM_SETEVENTMASK:
+  {
+    DWORD nOldMask = editor->nEventMask;
+    
     editor->nEventMask = lParam;
-    return 0;
+    return nOldMask;
+  }
   case EM_GETEVENTMASK:
     return editor->nEventMask;
   case EM_SETCHARFORMAT: