diff --git a/Library/Homebrew/extend/pathname.rb b/Library/Homebrew/extend/pathname.rb
index 3f898fecb4..284dc85f8c 100644
--- a/Library/Homebrew/extend/pathname.rb
+++ b/Library/Homebrew/extend/pathname.rb
@@ -239,7 +239,7 @@ class Pathname
   # @private
   def version
     require "version"
-    Version.parse(self)
+    Version.parse(basename)
   end
 
   # @private