diff --git a/src/Optimizely/UserProfile/UserProfileServiceInterface.php b/src/Optimizely/UserProfile/UserProfileServiceInterface.php
index 7d3a5269..8dc2ee7b 100644
--- a/src/Optimizely/UserProfile/UserProfileServiceInterface.php
+++ b/src/Optimizely/UserProfile/UserProfileServiceInterface.php
@@ -23,7 +23,7 @@ interface UserProfileServiceInterface
      *
      * @param $userId      string The ID of the user whose profile will be retrieved.
      *
-     * @return userProfile array  The user profile.
+     * @return array  The user profile.
      */
     public function lookup($userId);