diff --git a/Formula/knock.rb b/Formula/knock.rb
index 198f0b0a10..07608f88e6 100644
--- a/Formula/knock.rb
+++ b/Formula/knock.rb
@@ -12,7 +12,6 @@ class Knock < Formula
     sha256 "030dc0a7c3ea623eb3d8e11374f744ad79f8aee8b7b75210f1a183b4d6d978de" => :el_capitan
     sha256 "aac645d3c392386d99cb19200465a439639c8d3e7f8eac7021dbb677939cf155" => :yosemite
     sha256 "eb180c87d84707199ef6279a4709d76630a2089b331fb9ebc6c2bf58389fc921" => :mavericks
-    sha256 "3a60938c215acb144bff30f63eba43c79c471c090f8dd05171365396b64faf12" => :mountain_lion
   end
 
   head do