diff --git a/Gemfile b/Gemfile
index 1074a53be..d9ff4e524 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-ruby '>= 2.5.0', '< 2.8.0'
+ruby '>= 2.5.0', '< 3.1.0'
 gem 'bundler', '>= 1.12.0'
 
 gem 'rails', '6.1.3.1'
diff --git a/doc/INSTALL b/doc/INSTALL
index 3c2566984..c0d823b3e 100644
--- a/doc/INSTALL
+++ b/doc/INSTALL
@@ -7,7 +7,7 @@ http://www.redmine.org/
 
 == Requirements
 
-* Ruby 2.5, 2.6, 2.7
+* Ruby 2.5, 2.6, 2.7, 3.0
 * Bundler >= 1.12.0
 
 * A database: