diff --git a/.ruby-version b/.ruby-version
index 7921bd0c..1454f6ed 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.4.8
+4.0.1
diff --git a/Gemfile b/Gemfile
index 53b7aaea..1dab2131 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,7 +6,7 @@ end
 
 source 'https://rubygems.org'
 
-ruby '~> 3.3'
+ruby '~> 4.0'
 
 # as web framework
 if next?
diff --git a/Gemfile.lock b/Gemfile.lock
index f935daf1..bc4c7f86 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -766,7 +766,7 @@ DEPENDENCIES
   whenever
 
 RUBY VERSION
-   ruby 3.4.8
+   ruby 4.0.1
 
 BUNDLED WITH
    2.6.9