diff --git a/Gemfile b/Gemfile
index 88330b0736263f835317eef943cc2ffd06d98a76..508c7cfa34b22fc81d595b7bc4d6b71768fd8d9d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -49,7 +49,7 @@ gem "configurate", "0.3.1"
 
 # Cross-origin resource sharing
 
-gem "rack-cors", "0.3.1", require: "rack/cors"
+gem "rack-cors", "0.4.0", require: "rack/cors"
 
 # CSS
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 4240fbb74d4a3f525d96ec61f29b470f50319225..d29fa32d84d4269defa7ae48cc9ebb445d25791c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -461,7 +461,7 @@ GEM
     pry-debundle (0.8)
       pry
     rack (1.6.0)
-    rack-cors (0.3.1)
+    rack-cors (0.4.0)
     rack-google-analytics (1.2.0)
       actionpack
       activesupport
@@ -771,7 +771,7 @@ DEPENDENCIES
   pry
   pry-byebug
   pry-debundle
-  rack-cors (= 0.3.1)
+  rack-cors (= 0.4.0)
   rack-google-analytics (= 1.2.0)
   rack-piwik (= 0.3.0)
   rack-protection (= 1.5.3)