diff --git a/sql/sql_select.h b/sql/sql_select.h
index 5e9d570072e..07c0ca88e0f 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -903,6 +903,7 @@ protected:
     {   
       keyuse.elements= 0;
       keyuse.buffer= NULL;
+      keyuse.malloc_flags= 0;
       best_positions= 0;                        /* To detect errors */
       error= my_multi_malloc(MYF(MY_WME),
                              &best_positions,