diff --git a/Gemfile b/Gemfile
index 387ebe5e..1f8f1b94 100644
--- a/Gemfile
+++ b/Gemfile
@@ -20,7 +20,7 @@ gem 'nokogiri', "~> 1.10.4"
 gem 'jquery-rails'
 
 # bootstrap in sass in rails
-gem 'bootstrap-sass', '~> 3.1.1'
+gem 'bootstrap-sass', '~> 3.4.1'
 # wysihtml5 + bootstrap + asset pipeline
 gem 'bootstrap-wysihtml5-rails'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 07aa6a2c..f5453bdd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -33,14 +33,17 @@ GEM
     arel (3.0.3)
     auto_strip_attributes (2.0.6)
       activerecord (>= 3.0)
+    autoprefixer-rails (9.7.6)
+      execjs
     better_errors (2.1.1)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
       rack (>= 0.9.0)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
-    bootstrap-sass (3.1.1.1)
-      sass (~> 3.2)
+    bootstrap-sass (3.4.1)
+      autoprefixer-rails (>= 5.2.1)
+      sassc (>= 2.0.0)
     bootstrap-wysihtml5-rails (0.3.3.8)
       railties (>= 3.0)
     builder (3.0.4)
@@ -253,6 +256,8 @@ GEM
       railties (~> 3.2.0)
       sass (>= 3.1.10)
       tilt (~> 1.3)
+    sassc (2.4.0)
+      ffi (~> 1.9)
     select2-rails (3.5.4)
       thor (~> 0.14)
     sidekiq (2.17.7)
@@ -301,7 +306,7 @@ DEPENDENCIES
   auto_strip_attributes (~> 2.0)
   better_errors
   binding_of_caller
-  bootstrap-sass (~> 3.1.1)
+  bootstrap-sass (~> 3.4.1)
   bootstrap-wysihtml5-rails
   capatross
   capistrano (~> 2.15)