diff --git a/sinatra-contrib/lib/sinatra/required_params.rb b/sinatra-contrib/lib/sinatra/required_params.rb
index 53833418..c14525e4 100644
--- a/sinatra-contrib/lib/sinatra/required_params.rb
+++ b/sinatra-contrib/lib/sinatra/required_params.rb
@@ -60,7 +60,7 @@ module Sinatra
         elsif key.is_a?(Array)
           _required_params(p, *key)
         else
-          halt 400 unless p.has_key?(key.to_s)
+          halt 400 unless p && p.respond_to?(:has_key?) && p.has_key?(key.to_s)
         end
       end
       true