diff --git a/apps/oauth2/lib/Controller/LoginRedirectorController.php b/apps/oauth2/lib/Controller/LoginRedirectorController.php
index 7dbe6d902e477..b6bfb070441ef 100644
--- a/apps/oauth2/lib/Controller/LoginRedirectorController.php
+++ b/apps/oauth2/lib/Controller/LoginRedirectorController.php
@@ -89,7 +89,7 @@ public function authorize($client_id,
 
 		if ($response_type !== 'code') {
 			//Fail
-			$url = $client->getRedirectUri() . '?error=unsupported_response_type&state=' . $state;
+			$url = $client->getRedirectUri() . '?error=unsupported_response_type&state=' . \urlencode($state);
 			return new RedirectResponse($url);
 		}