diff --git a/ruby/lib/jam_ruby/models/recording.rb b/ruby/lib/jam_ruby/models/recording.rb
index d17861c16..dffdb485d 100644
--- a/ruby/lib/jam_ruby/models/recording.rb
+++ b/ruby/lib/jam_ruby/models/recording.rb
@@ -193,7 +193,7 @@ module JamRuby
         downloads.push(
             {
                 :type => "mix",
-                :id => mix.id,
+                :id => mix.id.to_s,
                 :recording_id => mix.recording_id,
                 :length => mix.length,
                 :md5 => mix.md5,