diff --git a/dlls/mshtml/tests/htmldoc.c b/dlls/mshtml/tests/htmldoc.c
index d1d02f0bf7b..641153baba7 100644
--- a/dlls/mshtml/tests/htmldoc.c
+++ b/dlls/mshtml/tests/htmldoc.c
@@ -837,6 +837,7 @@ static HRESULT WINAPI PropertyNotifySink_OnChanged(IPropertyNotifySink *iface, D
     case 3000028:
     case 3000029:
     case 3000030:
+    case 3000031:
         /* TODO */
         return S_OK;
     }