diff --git a/Gemfile b/Gemfile
index 6c74522..e95fbbd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ ruby '2.5.0'
 
 gem 'rails', '~> 5.2.0'
 gem 'sqlite3'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 gem 'bcrypt', '~> 3.1.7'
 gem 'mini_magick', '~> 4.8'
 gem 'bootsnap', '>= 1.1.0', require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 365ea1e..1c55c6a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -83,7 +83,9 @@ GEM
     marcel (0.3.2)
       mimemagic (~> 0.3.2)
     method_source (0.9.0)
-    mimemagic (0.3.2)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_magick (4.8.0)
     mini_mime (1.0.0)
     mini_portile2 (2.3.0)
@@ -92,7 +94,8 @@ GEM
     nio4r (2.3.1)
     nokogiri (1.8.4)
       mini_portile2 (~> 2.3.0)
-    puma (3.12.0)
+    puma (4.3.9)
+      nio4r (~> 2.0)
     rack (2.0.5)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -177,7 +180,7 @@ DEPENDENCIES
   jwt
   listen (>= 3.0.5, < 3.2)
   mini_magick (~> 4.8)
-  puma (~> 3.11)
+  puma (~> 4.3)
   rails (~> 5.2.0)
   rspec-rails
   spring