diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 56dd4fe..33f0c0f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,7 +6,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        ruby: [2.7, 3.0, 3.1, 3.2, 3.3, head, jruby, jruby-head, truffleruby, truffleruby-head]
+        ruby: [2.7, 3.0, 3.1, 3.2, 3.3, 3.4, head, jruby, jruby-head, truffleruby, truffleruby-head]
         exclude:
           - os: ubuntu-latest
             ruby: head
diff --git a/Gemfile.lock b/Gemfile.lock
index 34ca0c2..47fe06d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,24 +11,24 @@ GEM
   remote: https://rubygems.org/
   specs:
     base64 (0.2.0)
-    bigdecimal (3.1.8)
-    bigdecimal (3.1.8-java)
-    concurrent-ruby (1.2.2)
-    csv (3.2.8)
-    docile (1.4.0)
+    bigdecimal (3.1.9)
+    bigdecimal (3.1.9-java)
+    concurrent-ruby (1.3.5)
+    csv (3.3.2)
+    docile (1.4.1)
     hana (1.3.7)
-    i18n (1.14.1)
+    i18n (1.14.6)
       concurrent-ruby (~> 1.0)
     i18n-debug (1.2.0)
       i18n (< 2)
-    minitest (5.15.0)
-    rake (13.1.0)
-    regexp_parser (2.9.2)
+    minitest (5.25.4)
+    rake (13.2.1)
+    regexp_parser (2.10.0)
     simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
+    simplecov-html (0.13.1)
     simplecov_json_formatter (0.1.4)
     simpleidn (0.2.3)
 
@@ -38,7 +38,7 @@ PLATFORMS
 
 DEPENDENCIES
   base64
-  bundler (~> 2.0)
+  bundler (~> 2.4.0)
   csv
   i18n
   i18n-debug
@@ -48,4 +48,4 @@ DEPENDENCIES
   simplecov (~> 0.22)
 
 BUNDLED WITH
-   2.3.27
+   2.4.22
diff --git a/json_schemer.gemspec b/json_schemer.gemspec
index d905f82..2921d2b 100644
--- a/json_schemer.gemspec
+++ b/json_schemer.gemspec
@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 2.7'
 
   spec.add_development_dependency "base64"
-  spec.add_development_dependency "bundler", "~> 2.0"
+  spec.add_development_dependency "bundler", "~> 2.4.0"
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "minitest", "~> 5.0"
   spec.add_development_dependency "simplecov", "~> 0.22"
diff --git a/test/configuration_test.rb b/test/configuration_test.rb
index a4248bf..401e47f 100644
--- a/test/configuration_test.rb
+++ b/test/configuration_test.rb
@@ -1,7 +1,7 @@
 require 'test_helper'
 
 class ConfigurationTest < Minitest::Test
-  def run_configuration_test(option, default: (skip_default = true), test:)
+  def run_configuration_test(option, test:, default: (skip_default = true))
     original = JSONSchemer.configuration.public_send(option)
 
     if default.nil?
diff --git a/test/errors_test.rb b/test/errors_test.rb
index 38ee7dd..075b10f 100644
--- a/test/errors_test.rb
+++ b/test/errors_test.rb
@@ -26,13 +26,9 @@ def test_x_error
       'a' => 'foo',
       'b' => 'bar'
     }
-    assert_equal(
-      [
-        'properties a and b were provided, however only one or the other may be specified',
-        '{"a"=>"foo", "b"=>"bar"} `` /oneOf/1/not json-schemer://schema#/oneOf/1/not'
-      ].sort,
-      JSONSchemer.schema(schema).validate(data).map { |error| error.fetch('error') }.sort
-    )
+    error1, error2 = JSONSchemer.schema(schema).validate(data).map { |error| error.fetch('error') }.sort
+    assert_equal('properties a and b were provided, however only one or the other may be specified', error1)
+    assert_match(optional_space_regexp('{"a"', '=>', '"foo", "b"', '=>', '"bar"} `` /oneOf/1/not json-schemer://schema#/oneOf/1/not'), error2)
 
     assert_equal('schema error', JSONSchemer.schema(schema).validate(data, :output_format => 'basic').fetch('error'))
     assert_equal('oneOf error', JSONSchemer.schema(schema).validate(data, :output_format => 'detailed').fetch('error'))
@@ -220,7 +216,7 @@ def test_i18n_error
     end
 
     errors.delete('^')
-    assert_equal('I/9: {"yah"=>1} ``  https://example.com/schema#', i18n(errors) { schemer.validate(data, :output_format => 'basic').fetch('error') })
+    assert_match(optional_space_regexp('I/9: {"yah"', '=>', '1} ``  https://example.com/schema#'), i18n(errors) { schemer.validate(data, :output_format => 'basic').fetch('error') })
 
     errors.delete('type')
     assert_equal('I/9: 1 `/yah` /properties/yah/type https://example.com/schema#/properties/yah/type', i18n(errors) { schemer.validate(data).first.fetch('error') })
@@ -246,6 +242,10 @@ def test_i18n_error
 
 private
 
+  def optional_space_regexp(*parts)
+    /\A#{parts.map { |part| Regexp.escape(part) }.join('\s?')}\z/
+  end
+
   def i18n(errors)
     require 'yaml'
     require 'i18n'