diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index dd0a7d8dac..2862c47314 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -2217,7 +2217,6 @@ find_expr_references_walker(Node *node,
 		/* query_tree_walker ignores ORDER BY etc, but we need those opers */
 		find_expr_references_walker((Node *) query->sortClause, context);
 		find_expr_references_walker((Node *) query->groupClause, context);
-		find_expr_references_walker((Node *) query->windowClause, context);
 		find_expr_references_walker((Node *) query->distinctClause, context);
 
 		/* Examine substructure of query */
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 18bd5ac903..7f485ae29a 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -2292,6 +2292,8 @@ query_tree_walker(Query *query,
 		return true;
 	if (walker(query->havingQual, context))
 		return true;
+	if (walker(query->windowClause, context))
+		return true;
 	if (walker(query->limitOffset, context))
 		return true;
 	if (walker(query->limitCount, context))
@@ -3151,6 +3153,7 @@ query_tree_mutator(Query *query,
 	MUTATE(query->jointree, query->jointree, FromExpr *);
 	MUTATE(query->setOperations, query->setOperations, Node *);
 	MUTATE(query->havingQual, query->havingQual, Node *);
+	MUTATE(query->windowClause, query->windowClause, List *);
 	MUTATE(query->limitOffset, query->limitOffset, Node *);
 	MUTATE(query->limitCount, query->limitCount, Node *);
 	if (!(flags & QTW_IGNORE_CTE_SUBQUERIES))
diff --git a/src/backend/parser/parse_collate.c b/src/backend/parser/parse_collate.c
index 31a5f702a9..dabd904999 100644
--- a/src/backend/parser/parse_collate.c
+++ b/src/backend/parser/parse_collate.c
@@ -485,6 +485,7 @@ assign_collations_walker(Node *node, assign_collations_context *context)
 		case T_FromExpr:
 		case T_OnConflictExpr:
 		case T_SortGroupClause:
+		case T_WindowClause:
 			(void) expression_tree_walker(node,
 										  assign_collations_walker,
 										  (void *) &loccontext);