diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 28b153abc3..7518f83925 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1127,9 +1127,9 @@ EndPrepare(GlobalTransaction gxact)
 	replorigin = (replorigin_session_origin != InvalidRepOriginId &&
 				  replorigin_session_origin != DoNotReplicateId);
 
-	if (replorigin)
+	if (replorigin &&
+		replorigin_session_origin_lsn != InvalidXLogRecPtr)
 	{
-		Assert(replorigin_session_origin_lsn != InvalidXLogRecPtr);
 		hdr->origin_lsn = replorigin_session_origin_lsn;
 		hdr->origin_timestamp = replorigin_session_origin_timestamp;
 	}
diff --git a/contrib/test_decoding/expected/replorigin.out b/contrib/test_decoding/expected/replorigin.out
index 8077318755..895783d917 100644
--- a/contrib/test_decoding/expected/replorigin.out
+++ b/contrib/test_decoding/expected/replorigin.out
@@ -181,3 +181,65 @@ SELECT pg_replication_origin_drop('regress_test_decoding: regression_slot');
  
 (1 row)
 
+-- Transactions with no origin LSN and commit timestamps set for this
+-- session yet.
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_no_lsn', 'test_decoding');
+ ?column? 
+----------
+ init
+(1 row)
+
+SELECT pg_replication_origin_create('regress_test_decoding: regression_slot_no_lsn');
+ pg_replication_origin_create 
+------------------------------
+                            1
+(1 row)
+
+-- mark session as replaying
+SELECT pg_replication_origin_session_setup('regress_test_decoding: regression_slot_no_lsn');
+ pg_replication_origin_session_setup 
+-------------------------------------
+ 
+(1 row)
+
+-- Normal transaction
+BEGIN;
+INSERT INTO target_tbl(data)
+  SELECT data FROM
+    pg_logical_slot_get_changes('regression_slot_no_lsn', NULL, NULL, 'include-xids', '0');
+COMMIT;
+-- 2PC transaction
+BEGIN;
+INSERT INTO target_tbl(data)
+  SELECT data FROM
+    pg_logical_slot_get_changes('regression_slot_no_lsn', NULL, NULL, 'include-xids', '0');
+PREPARE TRANSACTION 'replorigin_prepared';
+COMMIT PREPARED 'replorigin_prepared';
+SELECT local_id, external_id,
+       remote_lsn <> '0/0' AS valid_remote_lsn,
+       local_lsn <> '0/0' AS valid_local_lsn
+       FROM pg_replication_origin_status;
+ local_id |                  external_id                  | valid_remote_lsn | valid_local_lsn 
+----------+-----------------------------------------------+------------------+-----------------
+        1 | regress_test_decoding: regression_slot_no_lsn | f                | t
+(1 row)
+
+-- This ensures that everything can be dropped.
+SELECT pg_replication_origin_session_reset();
+ pg_replication_origin_session_reset 
+-------------------------------------
+ 
+(1 row)
+
+SELECT pg_drop_replication_slot('regression_slot_no_lsn');
+ pg_drop_replication_slot 
+--------------------------
+ 
+(1 row)
+
+SELECT pg_replication_origin_drop('regress_test_decoding: regression_slot_no_lsn');
+ pg_replication_origin_drop 
+----------------------------
+ 
+(1 row)
+
diff --git a/contrib/test_decoding/sql/replorigin.sql b/contrib/test_decoding/sql/replorigin.sql
index b68f819fa1..87e57d50ea 100644
--- a/contrib/test_decoding/sql/replorigin.sql
+++ b/contrib/test_decoding/sql/replorigin.sql
@@ -87,3 +87,31 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc
 
 SELECT pg_drop_replication_slot('regression_slot');
 SELECT pg_replication_origin_drop('regress_test_decoding: regression_slot');
+
+-- Transactions with no origin LSN and commit timestamps set for this
+-- session yet.
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_no_lsn', 'test_decoding');
+SELECT pg_replication_origin_create('regress_test_decoding: regression_slot_no_lsn');
+-- mark session as replaying
+SELECT pg_replication_origin_session_setup('regress_test_decoding: regression_slot_no_lsn');
+-- Normal transaction
+BEGIN;
+INSERT INTO target_tbl(data)
+  SELECT data FROM
+    pg_logical_slot_get_changes('regression_slot_no_lsn', NULL, NULL, 'include-xids', '0');
+COMMIT;
+-- 2PC transaction
+BEGIN;
+INSERT INTO target_tbl(data)
+  SELECT data FROM
+    pg_logical_slot_get_changes('regression_slot_no_lsn', NULL, NULL, 'include-xids', '0');
+PREPARE TRANSACTION 'replorigin_prepared';
+COMMIT PREPARED 'replorigin_prepared';
+SELECT local_id, external_id,
+       remote_lsn <> '0/0' AS valid_remote_lsn,
+       local_lsn <> '0/0' AS valid_local_lsn
+       FROM pg_replication_origin_status;
+-- This ensures that everything can be dropped.
+SELECT pg_replication_origin_session_reset();
+SELECT pg_drop_replication_slot('regression_slot_no_lsn');
+SELECT pg_replication_origin_drop('regress_test_decoding: regression_slot_no_lsn');