diff --git a/lib/gollum/git_access.rb b/lib/gollum/git_access.rb
index 00ae88f0..409a0197 100644
--- a/lib/gollum/git_access.rb
+++ b/lib/gollum/git_access.rb
@@ -49,6 +49,8 @@ module Gollum
     def tree(ref)
       if sha = ref_to_sha(ref)
         get_cache(:tree, sha) { tree!(sha) }
+      else
+        []
       end
     end