diff --git a/Gemfile b/Gemfile
index 19ca37d..053149b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -45,7 +45,7 @@ gem 'jquery-rails', '~>2.3.0'
 
 # QR Codes
 gem 'rqrcode-rails3',  '~>0.1.7'
-gem 'mini_magick', '~>3.8.1'
+gem 'mini_magick', '~>4.11.0'
 
 gem 'sass-rails', "~> 4.0.3"
 gem 'coffee-rails', "~> 4.0.1"
diff --git a/Gemfile.lock b/Gemfile.lock
index 98127c9..d49a303 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -232,8 +232,7 @@ GEM
     mime-types (3.4.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2021.1115)
-    mini_magick (3.8.1)
-      subexec (~> 0.2.1)
+    mini_magick (4.11.0)
     mini_mime (1.1.2)
     mini_portile2 (2.8.0)
     minitest (5.14.4)
@@ -367,7 +366,6 @@ GEM
     sshkit (1.21.2)
       net-scp (>= 1.1.2)
       net-ssh (>= 2.8.0)
-    subexec (0.2.3)
     thor (1.1.0)
     thread_safe (0.3.6)
     tilt (1.4.1)
@@ -422,7 +420,7 @@ DEPENDENCIES
   jquery-ui-rails (~> 5.0.0)
   jquery-ui-themes (~> 0.0.11)
   libnotify (= 0.5.9)
-  mini_magick (~> 3.8.1)
+  mini_magick (~> 4.11.0)
   mysql2 (~> 0.5)
   poltergeist (~> 1.5.1)
   rack-ip-allowlist (~> 0.0.5)!