diff --git a/Gemfile b/Gemfile
index 72afb0782..158ae2939 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-ruby '>= 2.7.0', '< 3.3.0'
+ruby '>= 2.7.0', '< 3.4.0'
 
 gem 'rails', '7.1.2'
 gem 'rouge', '~> 4.2.0'
diff --git a/doc/INSTALL b/doc/INSTALL
index e8bc11d33..20267d99c 100644
--- a/doc/INSTALL
+++ b/doc/INSTALL
@@ -7,7 +7,7 @@ http://www.redmine.org/
 
 == Requirements
 
-* Ruby 2.7, 3.0, 3.1, 3.2
+* Ruby 2.7, 3.0, 3.1, 3.2, 3.3
 
 * A database:
   * MySQL (tested with MySQL 8)