diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 18d535c..317b3d5 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -21,6 +21,9 @@ jobs:
           - '3.0'
           - '3.1'
           - '3.2'
+          - '3.3'
+          - '3.4'
+          - '4.0'
 
     steps:
       - uses: actions/checkout@v4
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6ed33ef..43d72a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,13 +1,17 @@
 # Changelog
 
+## [1.9.1](https://github.com/puppetlabs/vmfloaty/tree/1.9.1) (2026-05-21)
+
+[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/1.9.0...1.9.1)
+
+**Merged pull requests:**
+
+- \(PA-8499\) Relax commander constraint [\#258](https://github.com/puppetlabs/vmfloaty/pull/258) ([mhashizume](https://github.com/mhashizume))
+
 ## [1.9.0](https://github.com/puppetlabs/vmfloaty/tree/1.9.0) (2026-05-01)
 
 [Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/1.8.1...1.9.0)
 
-**Breaking changes:**
-
-- Bump faraday from ~\> 1.5 to ~\> 2; raise minimum Ruby to 3.0 (drops Ruby 2.7 support) [\#256](https://github.com/puppetlabs/vmfloaty/pull/256) ([isaac-jha](https://github.com/isaac-jha))
-
 **Implemented enhancements:**
 
 - Bump simplecov-html from 0.12.3 to 0.13.1 [\#241](https://github.com/puppetlabs/vmfloaty/pull/241) ([dependabot[bot]](https://github.com/apps/dependabot))
@@ -48,6 +52,8 @@
 
 **Merged pull requests:**
 
+- Release prep for 1.9.0 [\#257](https://github.com/puppetlabs/vmfloaty/pull/257) ([isaac-jha](https://github.com/isaac-jha))
+- Bump faraday from ~\> 1.5 to ~\> 2 [\#256](https://github.com/puppetlabs/vmfloaty/pull/256) ([isaac-jha](https://github.com/isaac-jha))
 - Bump actions/setup-java from 3 to 4 [\#204](https://github.com/puppetlabs/vmfloaty/pull/204) ([dependabot[bot]](https://github.com/apps/dependabot))
 - Bump actions/github-script from 6 to 7 [\#202](https://github.com/puppetlabs/vmfloaty/pull/202) ([dependabot[bot]](https://github.com/apps/dependabot))
 - Bump rubocop from 1.56.3 to 1.56.4 [\#198](https://github.com/puppetlabs/vmfloaty/pull/198) ([dependabot[bot]](https://github.com/apps/dependabot))
@@ -242,19 +248,19 @@
 
 ## [v0.9.2-retag-for-gh-actions-for-real](https://github.com/puppetlabs/vmfloaty/tree/v0.9.2-retag-for-gh-actions-for-real) (2020-02-05)
 
-[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.2...v0.9.2-retag-for-gh-actions-for-real)
+[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.2-retag-for-gh-actions...v0.9.2-retag-for-gh-actions-for-real)
 
 **Merged pull requests:**
 
 - Update gempush action to remove GPR publish [\#66](https://github.com/puppetlabs/vmfloaty/pull/66) ([highb](https://github.com/highb))
 
-## [v0.9.2](https://github.com/puppetlabs/vmfloaty/tree/v0.9.2) (2020-02-05)
-
-[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.2-retag-for-gh-actions...v0.9.2)
-
 ## [v0.9.2-retag-for-gh-actions](https://github.com/puppetlabs/vmfloaty/tree/v0.9.2-retag-for-gh-actions) (2020-02-05)
 
-[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.0...v0.9.2-retag-for-gh-actions)
+[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.2...v0.9.2-retag-for-gh-actions)
+
+## [v0.9.2](https://github.com/puppetlabs/vmfloaty/tree/v0.9.2) (2020-02-05)
+
+[Full Changelog](https://github.com/puppetlabs/vmfloaty/compare/v0.9.0...v0.9.2)
 
 **Merged pull requests:**
 
diff --git a/Gemfile b/Gemfile
index 7f70b2e..a36f381 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,6 +7,8 @@ gemspec
 gem 'rake', require: false
 
 group :test do
+  # base64 is a bundled gem in Ruby >= 3.4, so it must be declared explicitly.
+  gem 'base64'
   gem 'simplecov', '~> 0.22.0'
   gem 'simplecov-html', '~> 0.13.1'
   gem 'simplecov-lcov', '~> 0.8.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 6dfa6ea..3336ffc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,8 +1,8 @@
 PATH
   remote: .
   specs:
-    vmfloaty (1.9.0)
-      commander (>= 4.4.3, < 4.7.0)
+    vmfloaty (1.9.1)
+      commander (>= 4.4.3, < 6)
       faraday (~> 2)
 
 GEM
@@ -11,10 +11,11 @@ GEM
     addressable (2.9.0)
       public_suffix (>= 2.0.2, < 8.0)
     ast (2.4.3)
+    base64 (0.3.0)
     bigdecimal (4.1.2)
     coderay (1.1.3)
-    commander (4.6.0)
-      highline (~> 2.0.0)
+    commander (5.0.0)
+      highline (~> 3.0.0)
     crack (1.0.1)
       bigdecimal
       rexml
@@ -27,7 +28,7 @@ GEM
     faraday-net_http (3.4.2)
       net-http (~> 0.5)
     hashdiff (1.2.1)
-    highline (2.0.3)
+    highline (3.0.1)
     io-console (0.8.2)
     json (2.19.4)
     language_server-protocol (3.17.0.5)
@@ -100,10 +101,12 @@ GEM
 
 PLATFORMS
   aarch64-linux
+  arm64-darwin-24
   x86_64-darwin-22
   x86_64-linux
 
 DEPENDENCIES
+  base64
   pry
   rake
   rb-readline
diff --git a/lib/vmfloaty/version.rb b/lib/vmfloaty/version.rb
index b5dc5cf..a3d780c 100644
--- a/lib/vmfloaty/version.rb
+++ b/lib/vmfloaty/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 class Vmfloaty
-  VERSION = '1.9.0'
+  VERSION = '1.9.1'
 end
diff --git a/vmfloaty.gemspec b/vmfloaty.gemspec
index 14c7ffa..e59e534 100644
--- a/vmfloaty.gemspec
+++ b/vmfloaty.gemspec
@@ -22,6 +22,6 @@ Gem::Specification.new do |s|
   s.require_path = 'lib'
   s.required_ruby_version = '>= 3.0'
 
-  s.add_dependency 'commander', '>= 4.4.3', '< 4.7.0'
+  s.add_dependency 'commander', '>= 4.4.3', '< 6'
   s.add_dependency 'faraday', '~> 2'
 end