diff --git a/src/include/replication/slotsync.h b/src/include/replication/slotsync.h
index 61e154b31b..e03c2a005a 100644
--- a/src/include/replication/slotsync.h
+++ b/src/include/replication/slotsync.h
@@ -27,7 +27,6 @@ extern char *CheckAndGetDbnameFromConninfo(void);
 extern bool ValidateSlotSyncParams(int elevel);
 
 extern void ReplSlotSyncWorkerMain(char *startup_data, size_t startup_data_len) pg_attribute_noreturn();
-extern int	StartSlotSyncWorker(void);
 
 extern void ShutDownSlotSync(void);
 extern bool SlotSyncWorkerCanRestart(void);