diff --git a/lib/cocoon/view_helpers.rb b/lib/cocoon/view_helpers.rb
index ed832a6..6d3da1c 100644
--- a/lib/cocoon/view_helpers.rb
+++ b/lib/cocoon/view_helpers.rb
@@ -33,7 +33,7 @@ module Cocoon
     # :nodoc:
     def render_association(association, f, new_object, render_options={}, custom_partial=nil)
       partial = setup_partial(custom_partial, association)
-      locals =  render_options.delete(:locals)
+      locals =  render_options.delete(:locals) || {}
       method_name = f.respond_to?(:semantic_fields_for) ? :semantic_fields_for : (f.respond_to?(:simple_fields_for) ? :simple_fields_for : :fields_for)
       f.send(method_name, association, new_object, {:child_index => "new_#{association}"}.merge(render_options)) do |builder|
         partial_options = {:f => builder, :dynamic => true}.merge(locals)