diff --git a/Library/Homebrew/rubocops/uses_from_macos.rb b/Library/Homebrew/rubocops/uses_from_macos.rb
index d21adfd8af..62b9f325d7 100644
--- a/Library/Homebrew/rubocops/uses_from_macos.rb
+++ b/Library/Homebrew/rubocops/uses_from_macos.rb
@@ -85,6 +85,7 @@ module RuboCop
           groff
           gzip
           less
+          mandoc
           openssl
           perl
           php