diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 40cc47ad25..09e8c06ffb 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -468,6 +468,7 @@ typedef struct ViewOptions
 #define RelationIsMapped(relation) \
 	((relation)->rd_rel->relfilenode == InvalidOid)
 
+#ifndef FRONTEND
 /*
  * RelationGetSmgr
  *		Returns smgr file handle for a relation, opening it if needed.
@@ -488,6 +489,7 @@ RelationGetSmgr(Relation rel)
 		smgrsetowner(&(rel->rd_smgr), smgropen(rel->rd_node, rel->rd_backend));
 	return rel->rd_smgr;
 }
+#endif							/* !FRONTEND */
 
 /*
  * RelationOpenSmgr