diff --git a/Gemfile b/Gemfile
index 471a044..4b6962f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -97,7 +97,7 @@ gem "octokit"
 gem 'jquery-textcomplete-rails'
 
 # https://github.com/twbs/bootstrap-sass
-gem 'bootstrap-sass', '~> 3.3.4'
+gem 'bootstrap-sass', '~> 3.4.1'
 
 # haml
 gem 'haml-rails'
diff --git a/Gemfile.lock b/Gemfile.lock
index a5016b4..404e2ec 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -69,9 +69,9 @@ GEM
     bindex (0.8.1)
     bootsnap (1.7.5)
       msgpack (~> 1.0)
-    bootstrap-sass (3.3.7)
+    bootstrap-sass (3.4.1)
       autoprefixer-rails (>= 5.2.1)
-      sass (>= 3.3.4)
+      sassc (>= 2.0.0)
     builder (3.2.4)
     byebug (11.1.3)
     capybara (3.35.3)
@@ -323,7 +323,7 @@ PLATFORMS
 
 DEPENDENCIES
   bootsnap (>= 1.1.0)
-  bootstrap-sass (~> 3.3.4)
+  bootstrap-sass (~> 3.4.1)
   byebug
   capybara (>= 2.15)
   chromedriver-helper