diff --git a/Gemfile b/Gemfile
index 132ee79..e162a99 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 #ruby "2.6.3"
 #ruby "3.2.2"
 gem 'sinatra', '~> 2.2'
-gem 'rmagick', '~> 4'
+gem 'rmagick', '~> 5'
 # Bundle edge Rails instead:
 # gem 'rails', :git => 'git://github.com/rails/rails.git'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index cbcab20..259e4fa 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,11 +3,13 @@ GEM
   specs:
     mustermann (2.0.2)
       ruby2_keywords (~> 0.0.1)
+    pkg-config (1.5.5)
     power_assert (2.0.3)
     rack (2.2.7)
     rack-protection (2.2.4)
       rack
-    rmagick (4.3.0)
+    rmagick (5.3.0)
+      pkg-config (~> 1.4)
     ruby2_keywords (0.0.5)
     sinatra (2.2.4)
       mustermann (~> 2.0)
@@ -22,7 +24,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  rmagick (~> 4)
+  rmagick (~> 5)
   sinatra (~> 2.2)
   test-unit (~> 3.3, >= 3.3.4)