diff --git a/.travis.yml b/.travis.yml
index a819d6f5b..17f2ac00a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ before_script:
   - npm install -g mocha-phantomjs@4.1.0
   - bundle exec rake test_js &> /dev/null &
   - sleep 5
+bundler_args: --frozen
 cache: bundler
 language: ruby
 rvm:
diff --git a/Gemfile.lock b/Gemfile.lock
index d2c5ea6a7..0c8412b93 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -17,7 +17,6 @@ GEM
     ast (2.4.0)
     backports (3.6.8)
     bcrypt (3.1.11)
-    builder (3.2.3)
     byebug (2.7.0)
       columnize (~> 0.3)
       debugger-linecache (~> 1.2)
@@ -73,7 +72,6 @@ GEM
     minitest (5.12.2)
     multi_json (1.14.1)
     multi_xml (0.6.0)
-    multipart-post (2.0.0)
     mustermann (1.0.3)
     nokogiri (1.11.0)
       mini_portile2 (~> 2.5.0)