diff --git a/server/wal/metrics.go b/server/wal/metrics.go
index 65e3c34a7..6f09deb51 100644
--- a/server/wal/metrics.go
+++ b/server/wal/metrics.go
@@ -47,5 +47,6 @@ var (
 
 func init() {
 	prometheus.MustRegister(walFsyncSec)
+	prometheus.MustRegister(walWriteSec)
 	prometheus.MustRegister(walWriteBytes)
 }