We solved this problem by proactively de-optimizing one of the pages so that the preferred page will rank for the target keyword. This includes removing the keyword from the Meta Title and all page headers to help alleviate it competing with your preferred ranking page. As long as Google's algorithm treats keyword cannibalization issues essentially the same. By making sure you only have one page attempting to rank for a target keyword a specific searcher intent, you give that page a chance to rank higher and make it easier for Google to index and rank your website's pages.