diff --git a/Formula/arpack.rb b/Formula/arpack.rb
index 98d5dc970c..6ea1eb3d13 100644
--- a/Formula/arpack.rb
+++ b/Formula/arpack.rb
@@ -3,6 +3,7 @@ class Arpack < Formula
   homepage "https://github.com/opencollab/arpack-ng"
   url "https://github.com/opencollab/arpack-ng/archive/3.7.0.tar.gz"
   sha256 "972e3fc3cd0b9d6b5a737c9bf6fd07515c0d6549319d4ffb06970e64fa3cc2d6"
+  revision 1
   head "https://github.com/opencollab/arpack-ng.git"
 
   bottle do