diff --git a/Library/Homebrew/cmd/update.rb b/Library/Homebrew/cmd/update.rb
index 7eac0b3896..e477bc7dc4 100644
--- a/Library/Homebrew/cmd/update.rb
+++ b/Library/Homebrew/cmd/update.rb
@@ -86,7 +86,7 @@ class RefreshBrew
   end
 
   def git_repo?
-    File.directory? '.git'
+    Dir['.git/*'].count > 0
   end
 
   def pending_formulae_changes?