diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 52f87895a66ad01d154bbf5aff89c927111f32f7..5468eb1b7707a5b686eb618a0afacb659d1d98b9 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -471,7 +471,7 @@ typedef struct
 #ifndef HAVE_SPINLOCKS
 	PGSemaphore	SpinlockSemaArray;
 #endif
-	LWLock	   *MainLWLockArray;
+	LWLockPadded *MainLWLockArray;
 	slock_t    *ProcStructLock;
 	PROC_HDR   *ProcGlobal;
 	PGPROC	   *AuxiliaryProcs;