Add canonical url tag and don't include query string

services/web/app/coffee/infrastructure/ExpressLocals.coffee

@@ -123,7 +123,9 @@ module.exports = (app, webRouter, apiRouter)->
 		res.locals.translate = (key, vars = {}) ->
 			vars.appName = Settings.appName
 			req.i18n.translate(key, vars)
-		res.locals.currentUrl = req.originalUrl
+		# Don't include the query string parameters, otherwise Google
+		# treats ?nocdn=true as the canonical version
+		res.locals.currentUrl = Url.parse(req.originalUrl).pathname
 		next()
 
 	webRouter.use (req, res, next)->

services/web/app/views/layout.jade

@@ -21,6 +21,7 @@ html(itemscope, itemtype='http://schema.org/Product')
 		link(rel="icon", href="/favicon.ico")
 		link(rel='stylesheet', href=buildCssPath('/style.css'))
 
+		link(rel="canonical", href=settings.siteUrl+currentUrl)
 		if settings.i18n.subdomainLang
 			each subdomainDetails in settings.i18n.subdomainLang
 				if !subdomainDetails.hide