diff --git a/dlls/mshtml/tests/htmldoc.c b/dlls/mshtml/tests/htmldoc.c
index 5306d845d35..2b32955c7be 100644
--- a/dlls/mshtml/tests/htmldoc.c
+++ b/dlls/mshtml/tests/htmldoc.c
@@ -2273,6 +2273,8 @@ static HRESULT QueryInterface(REFIID riid, void **ppv)
         *ppv = &OleControlSite;
     else if(IsEqualGUID(&IID_IDocHostShowUI, riid))
         return E_NOINTERFACE; /* TODO */
+    else if(IsEqualGUID(&IID_IProxyManager, riid))
+        return E_NOINTERFACE; /* ? */
     else if(IsEqualGUID(&IID_unk1, riid))
         return E_NOINTERFACE; /* HTMLWindow2 ? */
     else if(IsEqualGUID(&IID_unk2, riid))