diff --git a/src/viced/callback.c b/src/viced/callback.c
index f5d2b912c6..c8344cb719 100644
--- a/src/viced/callback.c
+++ b/src/viced/callback.c
@@ -1408,7 +1408,9 @@ BreakVolumeCallBacksLater(afs_uint32 volume)
 
     ViceLog(25, ("Fsync thread wakeup\n"));
 #ifdef AFS_PTHREAD_ENV
+    FSYNC_LOCK;
     assert(pthread_cond_broadcast(&fsync_cond) == 0);
+    FSYNC_UNLOCK;
 #else
     LWP_NoYieldSignal(fsync_wait);
 #endif