diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index ed8a734be7e..b49dfbaeec8 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -1956,6 +1956,7 @@ RemoveFromWaitQueue(PGPROC *proc, uint32 hashcode)
 	proc->waitLock = NULL;
 	proc->waitProcLock = NULL;
 	proc->waitStatus = PROC_WAIT_STATUS_ERROR;
+	pg_atomic_write_u64(&proc->waitStart, 0);
 
 	/*
 	 * Delete the proclock immediately if it represents no already-held locks.
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 450fb2a71d4..6a98b79bc3c 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -766,6 +766,9 @@ LockErrorCleanup(void)
 			GrantAwaitedLock();
 	}
 
+	/* An error can bypass ProcSleep()'s reset, so clear waitStart here */
+	pg_atomic_write_u64(&MyProc->waitStart, 0);
+
 	lockAwaited = NULL;
 
 	LWLockRelease(partitionLock);
@@ -1664,6 +1667,12 @@ ProcSleep(LOCALLOCK *locallock, LockMethod lockMethodTable)
 		}
 	} while (myWaitStatus == PROC_WAIT_STATUS_WAITING);
 
+	/*
+	 * Clear waitStart after the wait, as we may have set it after
+	 * ProcWakeup() cleared it.
+	 */
+	pg_atomic_write_u64(&MyProc->waitStart, 0);
+
 	/*
 	 * Disable the timers, if they are still running.  As in LockErrorCleanup,
 	 * we must preserve the LOCK_TIMEOUT indicator flag: if a lock timeout has