diff --git a/dlls/mshtml/htmlwindow.c b/dlls/mshtml/htmlwindow.c
index 39d54d6dbaf..5ed57017fee 100644
--- a/dlls/mshtml/htmlwindow.c
+++ b/dlls/mshtml/htmlwindow.c
@@ -101,25 +101,15 @@ static HRESULT WINAPI HTMLWindow2_GetTypeInfoCount(IHTMLWindow2 *iface, UINT *pc
 {
     HTMLWindow *This = HTMLWINDOW2_THIS(iface);
 
-    TRACE("(%p)->(%p)\n", This, pctinfo);
-
-    *pctinfo = 1;
-    return S_OK;
+    return IDispatchEx_GetTypeInfoCount(DISPATCHEX(This), pctinfo);
 }
 
 static HRESULT WINAPI HTMLWindow2_GetTypeInfo(IHTMLWindow2 *iface, UINT iTInfo,
                                               LCID lcid, ITypeInfo **ppTInfo)
 {
     HTMLWindow *This = HTMLWINDOW2_THIS(iface);
-    HRESULT hres;
 
-    TRACE("(%p)->(%u %u %p)\n", This, iTInfo, lcid, ppTInfo);
-
-    hres = get_typeinfo(IHTMLWindow2_tid, ppTInfo);
-    if(SUCCEEDED(hres))
-        ITypeInfo_AddRef(*ppTInfo);
-
-    return hres;
+    return IDispatchEx_GetTypeInfo(DISPATCHEX(This), iTInfo, lcid, ppTInfo);
 }
 
 static HRESULT WINAPI HTMLWindow2_GetIDsOfNames(IHTMLWindow2 *iface, REFIID riid,
@@ -127,17 +117,8 @@ static HRESULT WINAPI HTMLWindow2_GetIDsOfNames(IHTMLWindow2 *iface, REFIID riid
                                                 LCID lcid, DISPID *rgDispId)
 {
     HTMLWindow *This = HTMLWINDOW2_THIS(iface);
-    ITypeInfo *typeinfo;
-    HRESULT hres;
 
-    TRACE("(%p)->(%s %p %u %u %p)\n", This, debugstr_guid(riid), rgszNames, cNames,
-          lcid, rgDispId);
-
-    hres = get_typeinfo(IHTMLWindow2_tid, &typeinfo);
-    if(SUCCEEDED(hres))
-        hres = ITypeInfo_GetIDsOfNames(typeinfo, rgszNames, cNames, rgDispId);
-
-    return hres;
+    return IDispatchEx_GetIDsOfNames(DISPATCHEX(This), riid, rgszNames, cNames, lcid, rgDispId);
 }
 
 static HRESULT WINAPI HTMLWindow2_Invoke(IHTMLWindow2 *iface, DISPID dispIdMember,
@@ -145,18 +126,9 @@ static HRESULT WINAPI HTMLWindow2_Invoke(IHTMLWindow2 *iface, DISPID dispIdMembe
                             VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
 {
     HTMLWindow *This = HTMLWINDOW2_THIS(iface);
-    ITypeInfo *typeinfo;
-    HRESULT hres;
 
-    TRACE("(%p)->(%d %s %d %d %p %p %p %p)\n", This, dispIdMember, debugstr_guid(riid),
-          lcid, wFlags, pDispParams, pVarResult, pExcepInfo, puArgErr);
-
-    hres = get_typeinfo(IHTMLWindow2_tid, &typeinfo);
-    if(SUCCEEDED(hres))
-        hres = ITypeInfo_Invoke(typeinfo, HTMLWINDOW2(This), dispIdMember, wFlags, pDispParams,
-                pVarResult, pExcepInfo, puArgErr);
-
-    return hres;
+    return IDispatchEx_Invoke(DISPATCHEX(This), dispIdMember, riid, lcid, wFlags, pDispParams,
+            pVarResult, pExcepInfo, puArgErr);
 }
 
 static HRESULT WINAPI HTMLWindow2_item(IHTMLWindow2 *iface, VARIANT *pvarIndex, VARIANT *pvarResult)
@@ -794,16 +766,16 @@ static ULONG WINAPI HTMLWindow3_Release(IHTMLWindow3 *iface)
 static HRESULT WINAPI HTMLWindow3_GetTypeInfoCount(IHTMLWindow3 *iface, UINT *pctinfo)
 {
     HTMLWindow *This = HTMLWINDOW3_THIS(iface);
-    FIXME("(%p)->(%p)\n", This, pctinfo);
-    return E_NOTIMPL;
+
+    return IDispatchEx_GetTypeInfoCount(DISPATCHEX(This), pctinfo);
 }
 
 static HRESULT WINAPI HTMLWindow3_GetTypeInfo(IHTMLWindow3 *iface, UINT iTInfo,
                                               LCID lcid, ITypeInfo **ppTInfo)
 {
     HTMLWindow *This = HTMLWINDOW3_THIS(iface);
-    FIXME("(%p)->(%u %u %p)\n", This, iTInfo, lcid, ppTInfo);
-    return E_NOTIMPL;
+
+    return IDispatchEx_GetTypeInfo(DISPATCHEX(This), iTInfo, lcid, ppTInfo);
 }
 
 static HRESULT WINAPI HTMLWindow3_GetIDsOfNames(IHTMLWindow3 *iface, REFIID riid,
@@ -811,9 +783,8 @@ static HRESULT WINAPI HTMLWindow3_GetIDsOfNames(IHTMLWindow3 *iface, REFIID riid
                                                 LCID lcid, DISPID *rgDispId)
 {
     HTMLWindow *This = HTMLWINDOW3_THIS(iface);
-    FIXME("(%p)->(%s %p %u %u %p)\n", This, debugstr_guid(riid), rgszNames, cNames,
-          lcid, rgDispId);
-    return E_NOTIMPL;
+
+    return IDispatchEx_GetIDsOfNames(DISPATCHEX(This), riid, rgszNames, cNames, lcid, rgDispId);
 }
 
 static HRESULT WINAPI HTMLWindow3_Invoke(IHTMLWindow3 *iface, DISPID dispIdMember,
@@ -821,9 +792,9 @@ static HRESULT WINAPI HTMLWindow3_Invoke(IHTMLWindow3 *iface, DISPID dispIdMembe
                             VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
 {
     HTMLWindow *This = HTMLWINDOW3_THIS(iface);
-    FIXME("(%p)->(%d %s %d %d %p %p %p %p)\n", This, dispIdMember, debugstr_guid(riid),
-          lcid, wFlags, pDispParams, pVarResult, pExcepInfo, puArgErr);
-    return E_NOTIMPL;
+
+    return IDispatchEx_Invoke(DISPATCHEX(This), dispIdMember, riid, lcid, wFlags, pDispParams,
+            pVarResult, pExcepInfo, puArgErr);
 }
 
 static HRESULT WINAPI HTMLWindow3_get_screenLeft(IHTMLWindow3 *iface, long *p)