diff --git a/Library/Homebrew/keg.rb b/Library/Homebrew/keg.rb
index 9ebfc3bc3227ff7591d9c8505a59c488a724ca57..86733860cdee05b633322cc75fae489995f9129e 100644
--- a/Library/Homebrew/keg.rb
+++ b/Library/Homebrew/keg.rb
@@ -466,7 +466,7 @@ class Keg
   end
 
   def aliases
-    Formula[rack.basename.to_s].aliases
+    Formulary.from_rack(rack).aliases
   rescue FormulaUnavailableError
     []
   end