diff --git a/lib/travis/api/app.rb b/lib/travis/api/app.rb
index f1596b7d..25f482aa 100644
--- a/lib/travis/api/app.rb
+++ b/lib/travis/api/app.rb
@@ -185,7 +185,7 @@ module Travis::Api
                                          Travis.config.librato.token,
                                          Travis.config.librato_source
           on_error = proc {|ex| puts ex.message}
-          Metriks::LibratoMetricsReporter.new(email, token, source: source, prefix: prefix, on_error: on_error).start
+          Metriks::LibratoMetricsReporter.new(email, token, source: source, on_error: on_error).start
         end
       end