Google’s AdWords is about to get a small but important update in September, the company announced today. Until now, advertisers had two options when it came to how the company matches their ads to search queries: either only show the ad when the query exactly matched the keywords they set up in AdWords, or allow Google to also match the ad to keywords and phrases that are very similar to the original one, including variations like plurals or misspellings.

Starting in late September, that option is going away and Google will always automatically include all of these close variants when it tries to match an ad to a search query.

Google launched the variant-matching feature back in 2012. Today’s announcement only applies to what Google calls the “phrase match” and “exact match” options. As the name implies, exact match only shows the ad when the query exactly matched the keyword (say “women’s hats”), while phrase match also shows it when the query includes other words (like “buy women’s hats”).

Here is what this used to look like in the AdWords interface:

Advertisers will still be able to choose the even broader settings that include synonyms and other modifications, but they will not be able to lock down the match to just the exact keyword after late September. Instead, Google says it will always include misspellings, singular/plural forms, stemmings, accents, acronyms and abbreviations.”

That’s a big deal in the advertising world. Many advertisers like to have total control over when exactly their ads will appear, but Google is now taking some of that control away from them. In return, the company says that those advertisers who opted into close variant matching back in 2012 saw their clicks go up by 7 percent while their clickthrough and conversion rates remained about the same.

Google had already made close matching the default for most AdWords campaigns, so many advertisers won’t even notice the difference, but those that had always opted out because they wanted more control will surely be unhappy about this change.