diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 1389db1..c1bbf7b 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -45,6 +45,7 @@
 #include "optimizer/planner.h"
 #include "optimizer/prep.h"
 #include "optimizer/tlist.h"
+#include "optimizer/var.h"
 #include "parser/parse_coerce.h"
 #include "parser/parsetree.h"
 #include "utils/lsyscache.h"
@@ -107,7 +108,6 @@ static Bitmapset *translate_col_privs(const Bitmapset *parent_privs,
 					List *translated_vars);
 static Node *adjust_appendrel_attrs_mutator(Node *node,
 							   adjust_appendrel_attrs_context *context);
-static Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
 static List *adjust_inherited_tlist(List *tlist,
 					   AppendRelInfo *context);
 
@@ -1976,23 +1976,6 @@ adjust_appendrel_attrs_mutator(Node *node,
 }
 
 /*
- * Substitute newrelid for oldrelid in a Relid set
- */
-static Relids
-adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
-{
-	if (bms_is_member(oldrelid, relids))
-	{
-		/* Ensure we have a modifiable copy */
-		relids = bms_copy(relids);
-		/* Remove old, add new */
-		relids = bms_del_member(relids, oldrelid);
-		relids = bms_add_member(relids, newrelid);
-	}
-	return relids;
-}
-
-/*
  * Adjust the targetlist entries of an inherited UPDATE operation
  *
  * The expressions have already been fixed, but we have to make sure that
diff --git a/src/backend/optimizer/util/var.c b/src/backend/optimizer/util/var.c
index cf326ae..ccbed7a 100644
--- a/src/backend/optimizer/util/var.c
+++ b/src/backend/optimizer/util/var.c
@@ -840,3 +840,20 @@ alias_relid_set(PlannerInfo *root, Relids relids)
 	}
 	return result;
 }
+
+/*
+ * Substitute newrelid for oldrelid in a Relid set
+ */
+Relids
+adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
+{
+	if (bms_is_member(oldrelid, relids))
+	{
+		/* Ensure we have a modifiable copy */
+		relids = bms_copy(relids);
+		/* Remove old, add new */
+		relids = bms_del_member(relids, oldrelid);
+		relids = bms_add_member(relids, newrelid);
+	}
+	return relids;
+}
diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
index b23a3b7..55248c7 100644
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -18,6 +18,7 @@
 #include "nodes/nodeFuncs.h"
 #include "nodes/plannodes.h"
 #include "optimizer/clauses.h"
+#include "optimizer/var.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_relation.h"
 #include "parser/parsetree.h"
@@ -49,7 +50,6 @@ static bool locate_windowfunc_walker(Node *node,
 						 locate_windowfunc_context *context);
 static bool checkExprHasSubLink_walker(Node *node, void *context);
 static Relids offset_relid_set(Relids relids, int offset);
-static Relids adjust_relid_set(Relids relids, int oldrelid, int newrelid);
 
 
 /*
@@ -655,23 +655,6 @@ ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
 }
 
 /*
- * Substitute newrelid for oldrelid in a Relid set
- */
-static Relids
-adjust_relid_set(Relids relids, int oldrelid, int newrelid)
-{
-	if (bms_is_member(oldrelid, relids))
-	{
-		/* Ensure we have a modifiable copy */
-		relids = bms_copy(relids);
-		/* Remove old, add new */
-		relids = bms_del_member(relids, oldrelid);
-		relids = bms_add_member(relids, newrelid);
-	}
-	return relids;
-}
-
-/*
  * IncrementVarSublevelsUp - adjust Var nodes when pushing them down in tree
  *
  * Find all Var nodes in the given tree having varlevelsup >= min_sublevels_up,
diff --git a/src/include/optimizer/var.h b/src/include/optimizer/var.h
index ae1f856..4e24ab5 100644
--- a/src/include/optimizer/var.h
+++ b/src/include/optimizer/var.h
@@ -36,5 +36,6 @@ extern bool contain_vars_of_level(Node *node, int levelsup);
 extern int	locate_var_of_level(Node *node, int levelsup);
 extern List *pull_var_clause(Node *node, int flags);
 extern Node *flatten_join_alias_vars(PlannerInfo *root, Node *node);
+extern Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
 
 #endif   /* VAR_H */