diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index f1ec7d0db4..530cee4047 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -101,7 +101,7 @@ class Tab < OpenStruct
       :stdlib => nil,
       :compiler => "clang",
       :source => {
-        :path => nil,
+        :path => f ? f.path.to_s : nil,
       },
     }