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I'd actually do it the other way - redirect "index.php" to the root ("/") version - Google seems to prefer that and many of your inbound links will be to the root domain (people naturally default to it). Make sure your internal links point to that ("/") as well. See this post that expands on that and gives some .htaccess examples: http://www.searchmasters.co.nz/articles/78/redirecting-indexphp-to-root-using-htaccess/ You can add the canonical tag to help sweep up the problem, but I think it's best to have a solid 301-redirect in place here, especially if both versions are showing up in analytics.