diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index f029100cd8b..e36b1879476 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -1721,7 +1721,7 @@ ProcWakeup(PGPROC *proc, ProcWaitStatus waitStatus)
 	proc->waitLock = NULL;
 	proc->waitProcLock = NULL;
 	proc->waitStatus = waitStatus;
-	pg_atomic_write_u64(&MyProc->waitStart, 0);
+	pg_atomic_write_u64(&proc->waitStart, 0);
 
 	/* And awaken it */
 	SetLatch(&proc->procLatch);