diff --git a/invalid_domains.txt b/invalid_domains.txt
index 10debec..10862d1 100644
--- a/invalid_domains.txt
+++ b/invalid_domains.txt
@@ -204,7 +204,6 @@
 5.8.63.54
 5.9.253.173
 50.28.211.199
-503
 51.254.181.122
 51.254.19.227
 51.254.240.45