diff --git a/lib/active_resource/formats/json_format.rb b/lib/active_resource/formats/json_format.rb
index 827d1cc23a..b92ecc6ff8 100644
--- a/lib/active_resource/formats/json_format.rb
+++ b/lib/active_resource/formats/json_format.rb
@@ -18,6 +18,7 @@ def encode(hash, options = nil)
       end
 
       def decode(json)
+        return nil if json.nil?
         Formats.remove_root(ActiveSupport::JSON.decode(json))
       end
     end