diff --git a/lib/util/mio/readwritecloser.go b/lib/util/mio/readwritecloser.go
index 818861a8fd8742d45f2afe2b2546cbd1dd7e4fc6..35e8d89bb39a6e4d6349d3c8a0ec0851ad78b73c 100644
--- a/lib/util/mio/readwritecloser.go
+++ b/lib/util/mio/readwritecloser.go
@@ -58,7 +58,7 @@ func (T *ReadWriteCloser) Write(b []byte) (n int, err error) {
 		return 0, net.ErrClosed
 	}
 
-	if time.Now().After(T.writeDeadline) {
+	if T.writeDeadline != (time.Time{}) && time.Now().After(T.writeDeadline) {
 		return 0, context.DeadlineExceeded
 	}