diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index b0d85ba92a1..e50e744668a 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -760,7 +760,7 @@ public:
   void value_to_item(uint pos, Item *item)
   {
     ((Item_int*) item)->value= ((packed_longlong*) base)[pos].val;
-    ((Item_int*) item)->unsigned_flag= 
+    ((Item_int*) item)->unsigned_flag= (my_bool)
       ((packed_longlong*) base)[pos].unsigned_flag;
   }