diff --git a/dlls/mshtml/htmlwindow.c b/dlls/mshtml/htmlwindow.c
index 91b56f07682c16291a81003d498547736c4a1887..869b13c99443b723c6d786e4778f3ec2857b077c 100644
--- a/dlls/mshtml/htmlwindow.c
+++ b/dlls/mshtml/htmlwindow.c
@@ -995,8 +995,10 @@ static HRESULT WINAPI HTMLWindow3_get_screenTop(IHTMLWindow3 *iface, LONG *p)
 static HRESULT WINAPI HTMLWindow3_attachEvent(IHTMLWindow3 *iface, BSTR event, IDispatch *pDisp, VARIANT_BOOL *pfResult)
 {
     HTMLWindow *This = HTMLWINDOW3_THIS(iface);
-    FIXME("(%p)->(%s %p %p)\n", This, debugstr_w(event), pDisp, pfResult);
-    return E_NOTIMPL;
+
+    TRACE("(%p)->(%s %p %p)\n", This, debugstr_w(event), pDisp, pfResult);
+
+    return attach_event(&This->event_target, This->doc, event, pDisp, pfResult);
 }
 
 static HRESULT WINAPI HTMLWindow3_detachEvent(IHTMLWindow3 *iface, BSTR event, IDispatch *pDisp)