diff --git a/Gemfile b/Gemfile
index 010875e5..90c3dc6d 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 f6ea5cef..3ae0fca5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -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)
@@ -301,7 +301,7 @@ GEM
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff
-    webpacker (3.5.5)
+    webpacker (4.0.2)
       activesupport (>= 4.2)
       rack-proxy (>= 0.6.1)
       railties (>= 4.2)
@@ -353,7 +353,7 @@ DEPENDENCIES
   vcr (~> 4.0)
   web-console (>= 3.3.0)
   webmock (~> 3.5)
-  webpacker (~> 3.5)
+  webpacker (~> 4.0)
 
 BUNDLED WITH
    1.16.4