diff --git a/Gemfile b/Gemfile
index 5076926..8b2c5e9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -18,7 +18,7 @@ gem 'highlight_js-rails'
 gem 'jquery-rails'
 gem 'kaminari'
 gem 'pg'
-gem 'puma', '4.0.0'
+gem 'puma', '4.3.12'
 gem 'pundit'
 gem 'rack-cors', require: 'rack/cors'
 gem 'rails', '~> 5.2.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index c989059..0eab25f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -213,7 +213,9 @@ GEM
     mime-types (3.2.2)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.0331)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -223,7 +225,7 @@ GEM
     nenv (0.3.0)
     netrc (0.11.0)
     newrelic_rpm (6.5.0.357)
-    nio4r (2.4.0)
+    nio4r (2.5.8)
     nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     notiffany (0.1.3)
@@ -241,7 +243,7 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (3.1.1)
-    puma (4.0.0)
+    puma (4.3.12)
       nio4r (~> 2.0)
     pundit (2.1.0)
       activesupport (>= 3.0.0)
@@ -461,7 +463,7 @@ DEPENDENCIES
   pg
   poltergeist (>= 1.5.0)
   pry-rails
-  puma (= 4.0.0)
+  puma (= 4.3.12)
   pundit
   rack-cors
   rails (~> 5.2.3)