diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index 02c8f1aa8c..91cab876a2 100644
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -207,8 +207,8 @@ extern LWLock *LWLockAssign(void);
  * registration in the main shared memory segment wouldn't work for that case.
  */
 extern int	LWLockNewTrancheId(void);
-extern void LWLockRegisterTranche(int, LWLockTranche *);
-extern void LWLockInitialize(LWLock *, int tranche_id);
+extern void LWLockRegisterTranche(int tranche_id, LWLockTranche *tranche);
+extern void LWLockInitialize(LWLock *lock, int tranche_id);
 
 /*
  * Prior to PostgreSQL 9.4, we used an enum type called LWLockId to refer