diff --git a/Library/Homebrew/formula_auditor.rb b/Library/Homebrew/formula_auditor.rb
index b5e4494246909..b5093730bfa20 100644
--- a/Library/Homebrew/formula_auditor.rb
+++ b/Library/Homebrew/formula_auditor.rb
@@ -121,6 +121,8 @@ def self.aliases
     SYNCED_VERSIONS_FORMULAE_FILE = "synced_versions_formulae.json"
 
     def audit_synced_versions_formulae
+      return unless formula.tap
+
       synced_versions_formulae_file = formula.tap.path/SYNCED_VERSIONS_FORMULAE_FILE
       return unless synced_versions_formulae_file.file?