diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 0ba8fcd..c2aa582 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -36,7 +36,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.0
+        ruby-version: 3.1
         bundler-cache: true
     - run: bundle exec rake rbs:validate
 
@@ -46,7 +46,7 @@ jobs:
 
     strategy:
       matrix:
-        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4.0-preview1']
+        ruby-version: ['3.1', '3.2', '3.3', '3.4.0-preview1']
         cassandra-version: ['3', '4', '5']
 
     name: Linux, Cassandra ${{ matrix.cassandra-version }}, Ruby ${{ matrix.ruby-version }}
@@ -71,7 +71,7 @@ jobs:
 
     strategy:
       matrix:
-        ruby-version: ['3.0', '3.1', '3.2', '3.3', '3.4.0-preview1']
+        ruby-version: ['3.1', '3.2', '3.3', '3.4.0-preview1']
 
     name: macOS, Ruby ${{ matrix.ruby-version }}
     steps:
diff --git a/.rubocop.yml b/.rubocop.yml
index ada9a35..99365d0 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -6,7 +6,7 @@ require:
 
 AllCops:
     EnabledByDefault: true
-    TargetRubyVersion: 3.0
+    TargetRubyVersion: 3.1
 
 Bundler/GemComment:
   Enabled: false
@@ -91,6 +91,9 @@ Style/GlobalVars:
     - 'ext/ilios/extconf.rb'
     - 'test/helper.rb'
 
+Style/HashSyntax:
+  EnforcedShorthandSyntax: either
+
 Style/IpAddresses:
   Enabled: false
 
diff --git a/Gemfile b/Gemfile
index bb4be62..caa36a9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,8 +10,8 @@ gem 'rake', '~> 13.0'
 gem 'rake-compiler', '~> 1.2'
 gem 'rbs', '~> 3.4'
 gem 'rubocop', '~> 1.57'
-gem 'rubocop-minitest', '~> 0.33.0'
+gem 'rubocop-minitest', '~> 0.33'
 gem 'rubocop-performance', '~> 1.19'
 gem 'rubocop-rake', '~> 0.6'
 
-gem 'rubocop-on-rbs', '~> 0.2' if Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('3.1')
+gem 'rubocop-on-rbs', '~> 0.2'
diff --git a/ilios.gemspec b/ilios.gemspec
index 00808aa..377cb43 100644
--- a/ilios.gemspec
+++ b/ilios.gemspec
@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
   spec.description = 'Cassandra driver written by C language'
   spec.homepage = 'https://github.com/Watson1978/ilios'
   spec.license = 'MIT'
-  spec.required_ruby_version = '>= 3.0.0'
+  spec.required_ruby_version = '>= 3.1.0'
 
   spec.requirements << 'cmake'