diff --git includes/database/select.inc includes/database/select.inc
index 1609106..9046afb 100644
--- includes/database/select.inc
+++ includes/database/select.inc
@@ -1362,7 +1362,7 @@ class SelectQuery extends Query implements SelectQueryInterface {
     // Create our new query object that we will mutate into a count query.
     $count = clone($this);
 
-    $group_by = array_keys($count->getGroupBy());
+    $group_by = drupal_map_assoc(array_values($count->getGroupBy()));
 
     if (!$count->distinct) {
       // When not executing a distinct query, we can zero-out existing fields