diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index fc463faa6be..a0dfbf900a9 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -891,6 +891,12 @@ transformOnConflictClause(ParseState *pstate,
 	/* Process DO UPDATE */
 	if (onConflictClause->action == ONCONFLICT_UPDATE)
 	{
+		/*
+		 * All INSERT expressions have been parsed, get ready for potentially
+		 * existing SET statements that need to be processed like an UPDATE.
+		 */
+		pstate->p_is_insert = false;
+
 		exclRte = addRangeTableEntryForRelation(pstate,
 												pstate->p_target_relation,
 												makeAlias("excluded", NIL),
@@ -1999,7 +2005,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
 	Node	   *qual;
 
 	qry->commandType = CMD_UPDATE;
-	pstate->p_is_update = true;
+	pstate->p_is_insert = false;
 
 	/* process the WITH clause independently of all else */
 	if (stmt->withClause)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 3103b715944..7ecaffc0dc3 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -152,7 +152,6 @@ struct ParseState
 	bool		p_hasSubLinks;
 	bool		p_hasModifyingCTE;
 	bool		p_is_insert;
-	bool		p_is_update;
 	bool		p_locked_from_parent;
 	Relation	p_target_relation;
 	RangeTblEntry *p_target_rangetblentry;
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index 5f1532f2371..73fb5a248b4 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -1116,6 +1116,27 @@ select * from arr_tbl where f1 >= '{1,2,3}' and f1 < '{1,5,3}';
  {1,2,10}
 (2 rows)
 
+-- test ON CONFLICT DO UPDATE with arrays
+create temp table arr_pk_tbl (pk int4 primary key, f1 int[]);
+insert into arr_pk_tbl values (1, '{1,2,3}');
+insert into arr_pk_tbl values (1, '{3,4,5}') on conflict (pk)
+  do update set f1[1] = excluded.f1[1], f1[3] = excluded.f1[3]
+  returning pk, f1;
+ pk |   f1    
+----+---------
+  1 | {3,2,5}
+(1 row)
+
+insert into arr_pk_tbl(pk, f1[1:2]) values (1, '{6,7,8}') on conflict (pk)
+  do update set f1[1] = excluded.f1[1],
+    f1[2] = excluded.f1[2],
+    f1[3] = excluded.f1[3]
+  returning pk, f1;
+ pk |     f1     
+----+------------
+  1 | {6,7,NULL}
+(1 row)
+
 -- note: if above selects don't produce the expected tuple order,
 -- then you didn't get an indexscan plan, and something is busted.
 reset enable_seqscan;
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 562134b2863..b1dd6514405 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -306,6 +306,19 @@ set enable_seqscan to off;
 set enable_bitmapscan to off;
 select * from arr_tbl where f1 > '{1,2,3}' and f1 <= '{1,5,3}';
 select * from arr_tbl where f1 >= '{1,2,3}' and f1 < '{1,5,3}';
+
+-- test ON CONFLICT DO UPDATE with arrays
+create temp table arr_pk_tbl (pk int4 primary key, f1 int[]);
+insert into arr_pk_tbl values (1, '{1,2,3}');
+insert into arr_pk_tbl values (1, '{3,4,5}') on conflict (pk)
+  do update set f1[1] = excluded.f1[1], f1[3] = excluded.f1[3]
+  returning pk, f1;
+insert into arr_pk_tbl(pk, f1[1:2]) values (1, '{6,7,8}') on conflict (pk)
+  do update set f1[1] = excluded.f1[1],
+    f1[2] = excluded.f1[2],
+    f1[3] = excluded.f1[3]
+  returning pk, f1;
+
 -- note: if above selects don't produce the expected tuple order,
 -- then you didn't get an indexscan plan, and something is busted.
 reset enable_seqscan;