diff --git a/Gemfile b/Gemfile
index 07a1d45..ddb7f25 100644
--- a/Gemfile
+++ b/Gemfile
@@ -16,7 +16,7 @@ gemspec
 gem 'rails', '5.2.2'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 5.6'
 
 #
 gem 'sqlite3'
diff --git a/Gemfile.lock b/Gemfile.lock
index 3968003..e95e501 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -96,7 +96,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (0.9.2)
-    mimemagic (0.3.3)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
@@ -108,7 +110,8 @@ GEM
     nokogiri (1.9.1-x86-mingw32)
       mini_portile2 (~> 2.4.0)
     popper_js (1.14.5)
-    puma (3.12.0)
+    puma (5.6.4)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -205,7 +208,7 @@ DEPENDENCIES
   haml-rails (= 1.0.0)
   jquery-rails (~> 4.2.2)
   jquery-ui-rails
-  puma (~> 3.11)
+  puma (~> 5.6)
   rails (= 5.2.2)
   rails-assets-tether (>= 1.3.3)!
   sass-rails (~> 5.0.6)