diff --git a/dbcon/mysql/ha_calpont_execplan.cpp b/dbcon/mysql/ha_calpont_execplan.cpp
index 1094ffc37..7b33f4318 100644
--- a/dbcon/mysql/ha_calpont_execplan.cpp
+++ b/dbcon/mysql/ha_calpont_execplan.cpp
@@ -7138,7 +7138,9 @@ int getSelectPlan(gp_walk_info& gwi, SELECT_LEX& select_lex, SCSEP& csep, bool i
 
         // for subquery, order+limit by will be supported in infinidb. build order by columns
         // @todo union order by and limit support
-        if (gwi.hasWindowFunc || gwi.subSelectType != CalpontSelectExecutionPlan::MAIN_SELECT)
+        if (gwi.hasWindowFunc
+            || gwi.subSelectType != CalpontSelectExecutionPlan::MAIN_SELECT
+            || ( isUnion && ordercol ))
         {
             for (; ordercol; ordercol = ordercol->next)
             {