diff --git a/includes/database/database.inc b/includes/database/database.inc
index 1bfb3f7..54cad23 100644
--- a/includes/database/database.inc
+++ b/includes/database/database.inc
@@ -736,13 +736,14 @@ abstract class DatabaseConnection extends PDO {
     // to expand it out into a comma-delimited set of placeholders.
     foreach (array_filter($args, 'is_array') as $key => $data) {
       $new_keys = array();
+      $placeholder_index = 0;
       foreach ($data as $i => $value) {
         // This assumes that there are no other placeholders that use the same
         // name.  For example, if the array placeholder is defined as :example
         // and there is already an :example_2 placeholder, this will generate
         // a duplicate key.  We do not account for that as the calling code
         // is already broken if that happens.
-        $new_keys[$key . '_' . $i] = $value;
+        $new_keys[$key . '_' . $placeholder_index++] = $value;
       }
 
       // Update the query with the new placeholders.