diff --git a/transport/internet/kcp/connection.go b/transport/internet/kcp/connection.go
index f31e54f0b227..60e597cf2371 100644
--- a/transport/internet/kcp/connection.go
+++ b/transport/internet/kcp/connection.go
@@ -302,7 +302,7 @@ func (c *Connection) waitForDataInput() error {
 	select {
 	case <-c.dataInput.Wait():
 	case <-timeout.C:
-		if !c.rd.IsZero() && c.rd.Before(time.Now()) {
+		if c.rd.IsZero() || c.rd.Before(time.Now()) {
 			return ErrIOTimeout
 		}
 	}