diff --git a/Gemfile.lock b/Gemfile.lock
index e4f2559a..e6706c0a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -84,7 +84,7 @@ PATH
     travis-api (0.0.1)
       backports (~> 2.5)
       memcachier
-      mustermann (~> 0.3)
+      mustermann (~> 0.4)
       pg (~> 0.13.2)
       rack-contrib (~> 1.1)
       rack-ssl (~> 1.3, >= 1.3.3)
diff --git a/travis-api.gemspec b/travis-api.gemspec
index b65afd08..d98c31da 100644
--- a/travis-api.gemspec
+++ b/travis-api.gemspec
@@ -259,7 +259,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'thin',            '~> 1.4'
   s.add_dependency 'sinatra',         '~> 1.3'
   s.add_dependency 'sinatra-contrib', '~> 1.3'
-  s.add_dependency 'mustermann',      '~> 0.3'
+  s.add_dependency 'mustermann',      '~> 0.4'
   s.add_dependency 'redcarpet',       '~> 2.1'
   s.add_dependency 'rack-ssl',        '~> 1.3', '>= 1.3.3'
   s.add_dependency 'rack-contrib',    '~> 1.1'