diff --git a/Gemfile b/Gemfile
index 48b7c2e..0585783 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,7 +21,7 @@
 # SOFTWARE.
 
 source 'https://rubygems.org'
-ruby '~>3.2'
+ruby '~>4.0'
 
 Encoding.default_external = Encoding::UTF_8
 Encoding.default_internal = Encoding::UTF_8