You now have to go into Search Settings -> Verbatim. Unfortunately you’d have to do this for each search session as it doesn’t persist.

In Chrome, I've set up Google Verbatim as a search engine and made that the default address bar search. Here is the URL format: {google:baseURL}search?{google:RLZ}{google:acceptedSuggestion}{google:originalQueryForSuggestion}{google:searchFieldtrialParameter}{google:instantFieldTrialGroupParameter}sourceid=chrome&ie={inputEncoding}&q=%s&tbs=li:1

Especially when that word is 'not'.