diff --git a/router/sleeve.go b/router/sleeve.go
index 0be92572..1b4e2078 100644
--- a/router/sleeve.go
+++ b/router/sleeve.go
@@ -917,7 +917,7 @@ func (fwd *sleeveForwarder) processSendError(err error) error {
 			return nil
 		}
 
-		fwd.mtuHighestGood = 8
+		fwd.mtuHighestGood = 552
 		fwd.mtuLowestBad = mtu + 1
 		fwd.mtuCandidate = mtu
 		fwd.mtuTestsSent = 0