diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 35e9d0305f6..0dba25962ad 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -306,7 +306,7 @@ logicalrep_worker_launch(Oid dbid, Oid subid, const char *subname, Oid userid,
 
 	bgw.bgw_restart_time = BGW_NEVER_RESTART;
 	bgw.bgw_notify_pid = MyProcPid;
-	bgw.bgw_main_arg = slot;
+	bgw.bgw_main_arg = Int32GetDatum(slot);
 
 	if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
 	{
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 656d3999796..fa4f3b652d5 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -1441,7 +1441,7 @@ subscription_change_cb(Datum arg, int cacheid, uint32 hashvalue)
 void
 ApplyWorkerMain(Datum main_arg)
 {
-	int				worker_slot = DatumGetObjectId(main_arg);
+	int				worker_slot = DatumGetInt32(main_arg);
 	MemoryContext	oldctx;
 	char			originname[NAMEDATALEN];
 	XLogRecPtr		origin_startpos;