diff --git a/contrib/test_decoding/expected/stream.out b/contrib/test_decoding/expected/stream.out
index 0f21dcb8e0..2e319a8941 100644
--- a/contrib/test_decoding/expected/stream.out
+++ b/contrib/test_decoding/expected/stream.out
@@ -106,6 +106,26 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL,NULL, 'incl
  committing streamed transaction
 (17 rows)
 
+-- Test that accessing a TOAST table in streaming mode is allowed.
+-- Create a table with a column that uses a TOASTed default value.
+-- (temporarily hide query, to avoid the long CREATE TABLE stmt)
+\set ECHO none
+BEGIN;
+INSERT INTO test_tab SELECT repeat('a', 6000) || g.i FROM generate_series(1, 350) g(i);
+-- Force WAL flush, so that the above changes will be streamed.
+SELECT 'force flush' FROM pg_switch_wal();
+  ?column?   
+-------------
+ force flush
+(1 row)
+
+SELECT count(*) FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
+ count 
+-------
+   315
+(1 row)
+
+COMMIT;
 DROP TABLE stream_test;
 SELECT pg_drop_replication_slot('regression_slot');
  pg_drop_replication_slot 
diff --git a/contrib/test_decoding/sql/stream.sql b/contrib/test_decoding/sql/stream.sql
index 4feec62972..9502a6d87c 100644
--- a/contrib/test_decoding/sql/stream.sql
+++ b/contrib/test_decoding/sql/stream.sql
@@ -44,5 +44,23 @@ toasted-123456789012345678901234567890123456789012345678901234567890123456789012
 
 SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL,NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
 
+-- Test that accessing a TOAST table in streaming mode is allowed.
+
+-- Create a table with a column that uses a TOASTed default value.
+-- (temporarily hide query, to avoid the long CREATE TABLE stmt)
+\set ECHO none
+SELECT 'CREATE TABLE test_tab (a text DEFAULT ''' || string_agg('toast value', '') || ''');' FROM generate_series(1, 4000)
+\gexec
+\set ECHO all
+
+BEGIN;
+INSERT INTO test_tab SELECT repeat('a', 6000) || g.i FROM generate_series(1, 350) g(i);
+
+-- Force WAL flush, so that the above changes will be streamed.
+SELECT 'force flush' FROM pg_switch_wal();
+
+SELECT count(*) FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
+COMMIT;
+
 DROP TABLE stream_test;
 SELECT pg_drop_replication_slot('regression_slot');
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index ede9660c9e..76d3edd470 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -703,6 +703,14 @@ systable_beginscan_ordered(Relation heapRelation,
 	index_rescan(sysscan->iscan, key, nkeys, NULL, 0);
 	sysscan->scan = NULL;
 
+	/*
+	 * If CheckXidAlive is set then set a flag to indicate that system table
+	 * scan is in-progress.  See detailed comments in xact.c where these
+	 * variables are declared.
+	 */
+	if (TransactionIdIsValid(CheckXidAlive))
+		bsysscan = true;
+
 	return sysscan;
 }
 
@@ -747,6 +755,14 @@ systable_endscan_ordered(SysScanDesc sysscan)
 	index_endscan(sysscan->iscan);
 	if (sysscan->snapshot)
 		UnregisterSnapshot(sysscan->snapshot);
+
+	/*
+	 * Reset the bsysscan flag at the end of the systable scan.  See detailed
+	 * comments in xact.c where these variables are declared.
+	 */
+	if (TransactionIdIsValid(CheckXidAlive))
+		bsysscan = false;
+
 	pfree(sysscan);
 }