diff --git a/src/backend/catalog/pg_publication.c b/src/backend/catalog/pg_publication.c
index 63579b2f82..b40293fcb3 100644
--- a/src/backend/catalog/pg_publication.c
+++ b/src/backend/catalog/pg_publication.c
@@ -487,6 +487,10 @@ GetPublicationRelations(Oid pubid, PublicationPartOpt pub_partopt)
 	systable_endscan(scan);
 	table_close(pubrelsrel, AccessShareLock);
 
+	/* Now sort and de-duplicate the result list */
+	list_sort(result, list_oid_cmp);
+	list_deduplicate_oid(result);
+
 	return result;
 }
 
diff --git a/src/test/regress/expected/publication.out b/src/test/regress/expected/publication.out
index 1feb558968..a2115c1c60 100644
--- a/src/test/regress/expected/publication.out
+++ b/src/test/regress/expected/publication.out
@@ -832,6 +832,14 @@ SELECT * FROM pg_publication_tables;
  pub     | sch2       | tbl1_part1
 (1 row)
 
+-- Table publication that includes both the parent table and the child table
+ALTER PUBLICATION pub ADD TABLE sch1.tbl1;
+SELECT * FROM pg_publication_tables;
+ pubname | schemaname | tablename  
+---------+------------+------------
+ pub     | sch2       | tbl1_part1
+(1 row)
+
 DROP PUBLICATION pub;
 DROP TABLE sch2.tbl1_part1;
 DROP TABLE sch1.tbl1;
diff --git a/src/test/regress/sql/publication.sql b/src/test/regress/sql/publication.sql
index 8fa0435c32..2fe41b07ae 100644
--- a/src/test/regress/sql/publication.sql
+++ b/src/test/regress/sql/publication.sql
@@ -469,6 +469,10 @@ DROP PUBLICATION pub;
 CREATE PUBLICATION pub FOR TABLE sch2.tbl1_part1 WITH (PUBLISH_VIA_PARTITION_ROOT=0);
 SELECT * FROM pg_publication_tables;
 
+-- Table publication that includes both the parent table and the child table
+ALTER PUBLICATION pub ADD TABLE sch1.tbl1;
+SELECT * FROM pg_publication_tables;
+
 DROP PUBLICATION pub;
 DROP TABLE sch2.tbl1_part1;
 DROP TABLE sch1.tbl1;