diff --git a/sql/sql_select.h b/sql/sql_select.h
index 9051b7fd2b8..ecfa4c6fd11 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -1289,7 +1289,7 @@ public:
 
 #ifndef DBUG_OFF
   void dbug_verify_sj_inner_tables(uint n_positions) const;
-  uint dbug_join_tab_array_size;
+  int dbug_join_tab_array_size;
 #endif
 
   /* We also maintain a stack of join optimization states in * join->positions[] */