diff --git a/Gemfile b/Gemfile
index c2a937f5..18c006ce 100644
--- a/Gemfile
+++ b/Gemfile
@@ -29,7 +29,7 @@ gem 'sass-rails', '~> 5.0'
 gem 'slack-notifier', '~> 2.3.2'
 gem 'turbolinks', '~> 5'
 gem 'uglifier', '>= 1.3.0'
-gem 'webpacker', '~> 3.5'
+gem 'webpacker', '~> 4.0'
 
 group :test do
   gem 'capybara', '~> 2.18'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7e42701d..13b664ef 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -127,7 +127,7 @@ GEM
       activesupport (>= 5.0)
       request_store (>= 1.0)
     encryptor (3.0.0)
-    erubi (1.8.0)
+    erubi (1.9.0)
     execjs (2.7.0)
     factory_bot (5.0.2)
       activesupport (>= 4.2.0)
@@ -146,7 +146,7 @@ GEM
       bootstrap (~> 4.1.3)
       rails (>= 4.2.0)
       sass-rails
-    i18n (1.6.0)
+    i18n (1.7.0)
       concurrent-ruby (~> 1.0)
     io-like (0.3.0)
     jmespath (1.3.1)
@@ -168,7 +168,7 @@ GEM
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
     local_time (2.1.0)
-    loofah (2.2.3)
+    loofah (2.3.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
@@ -180,7 +180,7 @@ GEM
     mimemagic (0.3.3)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
-    minitest (5.11.3)
+    minitest (5.12.2)
     minitest-capybara (0.8.2)
       capybara (~> 2.2)
       minitest (~> 5.0)
@@ -210,7 +210,7 @@ GEM
     puma (3.12.1)
     rack (2.0.7)
     rack-cors (1.0.3)
-    rack-proxy (0.6.4)
+    rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -230,15 +230,15 @@ GEM
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
     railties (5.2.3)
       actionpack (= 5.2.3)
       activesupport (= 5.2.3)
       method_source
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
-    rake (12.3.2)
+    rake (13.0.0)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
@@ -301,7 +301,7 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    webpacker (3.5.5)
+    webpacker (4.0.7)
       activesupport (>= 4.2)
       rack-proxy (>= 0.6.1)
       railties (>= 4.2)
@@ -353,7 +353,7 @@ DEPENDENCIES
   vcr (~> 5.0)
   web-console (>= 3.3.0)
   webmock (~> 3.7)
-  webpacker (~> 3.5)
+  webpacker (~> 4.0)
 
 BUNDLED WITH
    1.16.4