diff --git a/lib/rails-footnotes/filter.rb b/lib/rails-footnotes/filter.rb
index 803d2e6..2b8cf53 100644
--- a/lib/rails-footnotes/filter.rb
+++ b/lib/rails-footnotes/filter.rb
@@ -65,7 +65,9 @@ def initialize(controller)
       @notes = []
 
       revert_pos(controller.response_body) do
-        @body = controller.response.body
+        if controller.response.stream.respond_to?(:body)
+          @body = controller.response.body
+        end
       end
     end