diff --git a/lib/neography/rest.rb b/lib/neography/rest.rb
index d08baba..9f35696 100644
--- a/lib/neography/rest.rb
+++ b/lib/neography/rest.rb
@@ -426,6 +426,8 @@ def get_batch(args)
             {:method => "GET", :to => "/index/node/#{args[1]}/#{args[2]}/#{args[3]}"}
           when :get_relationship_index
             {:method => "GET", :to => "/index/relationship/#{args[1]}/#{args[2]}/#{args[3]}"}
+          else
+            raise "Unknown option #{args[0]}"
         end
      end