diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 6d003cc8e5..09d5f0f571 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -1539,6 +1539,8 @@ convert_EXISTS_sublink_to_join(PlannerInfo *root, SubLink *sublink,
 static bool
 simplify_EXISTS_query(PlannerInfo *root, Query *query)
 {
+	ListCell   *lc;
+
 	/*
 	 * We don't try to simplify at all if the query uses set operations,
 	 * aggregates, grouping sets, SRFs, modifying CTEs, HAVING, OFFSET, or FOR
@@ -1607,6 +1609,28 @@ simplify_EXISTS_query(PlannerInfo *root, Query *query)
 	query->sortClause = NIL;
 	query->hasDistinctOn = false;
 
+	/*
+	 * Since we have thrown away the GROUP BY clauses, we'd better remove the
+	 * RTE_GROUP RTE and clear the hasGroupRTE flag.
+	 */
+	foreach(lc, query->rtable)
+	{
+		RangeTblEntry *rte = lfirst_node(RangeTblEntry, lc);
+
+		/*
+		 * Remove the RTE_GROUP RTE and clear the hasGroupRTE flag.  (Since
+		 * we'll exit the foreach loop immediately, we don't bother with
+		 * foreach_delete_current.)
+		 */
+		if (rte->rtekind == RTE_GROUP)
+		{
+			Assert(query->hasGroupRTE);
+			query->rtable = list_delete_cell(query->rtable, lc);
+			query->hasGroupRTE = false;
+			break;
+		}
+	}
+
 	return true;
 }
 
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 5669ed929a..9b2973694f 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -3182,6 +3182,21 @@ where b.unique2 is null;
          ->  Index Only Scan using tenk1_unique2 on tenk1 b
 (5 rows)
 
+--
+-- regression test for bogus RTE_GROUP entries
+--
+explain (costs off)
+select a.* from tenk1 a
+where exists (select 1 from tenk1 b where a.unique1 = b.unique2 group by b.unique1);
+                         QUERY PLAN                         
+------------------------------------------------------------
+ Hash Semi Join
+   Hash Cond: (a.unique1 = b.unique2)
+   ->  Seq Scan on tenk1 a
+   ->  Hash
+         ->  Index Only Scan using tenk1_unique2 on tenk1 b
+(5 rows)
+
 --
 -- regression test for proper handling of outer joins within antijoins
 --
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 73474bb64f..4c9c3e9f49 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -818,6 +818,14 @@ explain (costs off)
 select a.* from tenk1 a left join tenk1 b on a.unique1 = b.unique2
 where b.unique2 is null;
 
+--
+-- regression test for bogus RTE_GROUP entries
+--
+
+explain (costs off)
+select a.* from tenk1 a
+where exists (select 1 from tenk1 b where a.unique1 = b.unique2 group by b.unique1);
+
 --
 -- regression test for proper handling of outer joins within antijoins
 --