diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index e93458d..ab43515 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -12,18 +12,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: ["3.1", "3.2", "3.3", "3.4", "4.0"]
+        ruby: ["3.2", "3.3", "3.4", "4.0"]
         gemfile: [
           dev/gemfiles/rails-7.2.x.gemfile,
           dev/gemfiles/rails-8.0.x.gemfile,
           Gemfile
         ]
-        exclude:
-          # Exclude rubies < 3.2 for ActiveModel < 8.0
-          - ruby: "3.1"
-            gemfile: dev/gemfiles/rails-8.0.x.gemfile
-          - ruby: "3.1"
-            gemfile: Gemfile
     env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps
       BUNDLE_GEMFILE: ${{ github.workspace }}/${{ matrix.gemfile }}
     steps:
diff --git a/.rubocop.yml b/.rubocop.yml
index 196aeeb..af4a8a6 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,7 +4,7 @@ plugins:
   - rubocop-rspec
 
 AllCops:
-  TargetRubyVersion: 3.1
+  TargetRubyVersion: 3.2
   NewCops: enable
 
 Naming/FileName:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0f8d1f1..f6c8de4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Changed
 
+* Remove Ruby 3.1 from the test matrix (#14)
 * Add Ruby 4.0 to the test matrix (#23)
 
 ## Version 1.1.0 (2025-10-23)
diff --git a/postcode_validator.gemspec b/postcode_validator.gemspec
index b472d0f..c330f4f 100644
--- a/postcode_validator.gemspec
+++ b/postcode_validator.gemspec
@@ -36,7 +36,7 @@ Gem::Specification.new do |spec|
     f.match(excluded_dirs) || excluded_files.include?(f)
   end
 
-  spec.required_ruby_version = '>= 3.1'
+  spec.required_ruby_version = '>= 3.2'
 
   spec.add_dependency 'twitter_cldr', '> 4.4.0'