diff --git a/Gemfile b/Gemfile
index 976d7bc83..7b61b5007 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-ruby '>= 2.5.0', '< 3.1.0'
+ruby '>= 2.5.0', '< 3.2.0'
 gem 'bundler', '>= 1.12.0'
 
 gem 'rails', '6.1.4.4'
diff --git a/doc/INSTALL b/doc/INSTALL
index c0d823b3e..958e54118 100644
--- a/doc/INSTALL
+++ b/doc/INSTALL
@@ -7,7 +7,7 @@ http://www.redmine.org/
 
 == Requirements
 
-* Ruby 2.5, 2.6, 2.7, 3.0
+* Ruby 2.5, 2.6, 2.7, 3.0, 3.1
 * Bundler >= 1.12.0
 
 * A database: