Recent Global Post Widget and Groups

I'm using the Recent Global Post Widget which so far is functioning really well.
Yesterday I installed the Plugin Groups. I set it up so some articles are only shown to members of a group. Everythin ist working alright (inside the blog I can only see a restricted articel when I'm logged in as a member of the group) BUT I can see the restricted articles in the Recent Global Posts Widget even when I'm not a member of the group.
How can I hide those articles in the widget for users who are not allowed to read it?