diff --git a/Gemfile b/Gemfile
index 0ab5485..448c4b7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -20,7 +20,7 @@ gem "graphiql-rails", "1.4.5"
 gem "graphql", "1.7.4"
 
 gem "envied", "0.9.1"
-gem "puma", "3.10.0"
+gem "puma", "4.3.12"
 
 group :development, :test do
   gem "pry-rails", "0.3.6"
diff --git a/Gemfile.lock b/Gemfile.lock
index 91bd543..8f111f0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -135,7 +135,8 @@ GEM
     pry-rails (0.3.6)
       pry (>= 0.10.4)
     public_suffix (3.0.0)
-    puma (3.10.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.3)
     rack-test (0.7.0)
       rack (>= 1.0, < 3)
@@ -280,7 +281,7 @@ DEPENDENCIES
   listen (= 3.1.5)
   pg (= 0.21.0)
   pry-rails (= 0.3.6)
-  puma (= 3.10.0)
+  puma (= 4.3.12)
   rails (= 5.1.4)
   rom (= 4.0.1)
   rom-rails (= 1.0.0)