diff --git a/modules/user/user.install b/modules/user/user.install
index 8522796..9b9e678 100644
--- a/modules/user/user.install
+++ b/modules/user/user.install
@@ -236,6 +236,7 @@ function user_schema() {
       'access' => array('access'),
       'created' => array('created'),
       'mail' => array('mail'),
+      'picture' => array('picture'),
     ),
     'unique keys' => array(
       'name' => array('name'),
@@ -892,3 +893,21 @@ function user_update_7017() {
 /**
  * @} End of "addtogroup updates-6.x-to-7.x"
  */
+
+/**
+ * @addtogroup updates-7.x-extra
+ * @{
+ */
+
+/**
+ * Ensure there is an index on {user}.picture.
+ */
+function user_update_7018() {
+  if (!db_index_exists('users', 'picture')) {
+    db_add_index('users', 'picture', array('picture'));
+  }
+}
+
+/**
+ * @} End of "addtogroup updates-7.x-extra"
+ */