diff --git a/net/netcheck/netcheck.go b/net/netcheck/netcheck.go
index 408d92780..80957039e 100644
--- a/net/netcheck/netcheck.go
+++ b/net/netcheck/netcheck.go
@@ -345,7 +345,7 @@ func (p probeProto) String() string {
 	case probeIPv4:
 		return "v4"
 	case probeIPv6:
-		return "v4"
+		return "v6"
 	case probeHTTPS:
 		return "https"
 	}