diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index 09734fc964..d13466fd0e 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -520,6 +520,7 @@ module Homebrew
         gnupg@1.4
         lua@5.1
         numpy@1.16
+        libsigc++@2
       ].freeze
 
       return if keg_only_whitelist.include?(formula.name) || formula.name.start_with?("gcc@")