diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 36393b0..567fd5e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,65 +10,15 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version:
-          - 2.7
-          - '3.0'
-          - 3.1
           - 3.2
           - 3.3
           - 3.4
+          - '4.0'
         rails-version:
-          - '6.0'
-          - 6.1
-          - '7.0'
           - 7.1
           - 7.2
           - '8.0'
           - 8.1
-        exclude:
-          - ruby-version: 2.7
-            rails-version: 7.1
-          - ruby-version: 2.7
-            rails-version: 7.2
-          - ruby-version: 2.7
-            rails-version: 8.0
-          - ruby-version: 2.7
-            rails-version: 8.1
-          - ruby-version: 3.0
-            rails-version: 6.0
-          - ruby-version: 3.0
-            rails-version: 7.1
-          - ruby-version: 3.0
-            rails-version: 7.2
-          - ruby-version: 3.0
-            rails-version: 8.0
-          - ruby-version: 3.0
-            rails-version: 8.1
-          - ruby-version: 3.1
-            rails-version: 6.0
-          - ruby-version: 3.1
-            rails-version: 6.1
-          - ruby-version: 3.1
-            rails-version: 8.0
-          - ruby-version: 3.1
-            rails-version: 8.1
-          - ruby-version: 3.2
-            rails-version: 6.0
-          - ruby-version: 3.2
-            rails-version: 6.1
-          - ruby-version: 3.2
-            rails-version: 7.0
-          - ruby-version: 3.3
-            rails-version: 6.0
-          - ruby-version: 3.3
-            rails-version: 6.1
-          - ruby-version: 3.3
-            rails-version: 7.0
-          - ruby-version: 3.4
-            rails-version: 6.0
-          - ruby-version: 3.4
-            rails-version: 6.1
-          - ruby-version: 3.4
-            rails-version: 7.0
     env:
       BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/rails_${{ matrix.rails-version }}.gemfile
     steps:
diff --git a/Appraisals b/Appraisals
index ccfafc6..2087dcc 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,18 +1,3 @@
-appraise "rails-6.0" do
-  gem "activesupport", "~> 6.0.0"
-  gem 'concurrent-ruby', '1.3.4'
-end
-
-appraise "rails-6.1" do
-  gem "activesupport", "~> 6.1.0"
-  gem 'concurrent-ruby', '1.3.4'
-end
-
-appraise "rails-7.0" do
-  gem "activesupport", "~> 7.0.0"
-  gem 'concurrent-ruby', '1.3.4'
-end
-
 appraise "rails-7.1" do
   gem "activesupport", "~> 7.1.0"
 end
diff --git a/gemfiles/rails_6.0.gemfile b/gemfiles/rails_6.0.gemfile
deleted file mode 100644
index cac0fde..0000000
--- a/gemfiles/rails_6.0.gemfile
+++ /dev/null
@@ -1,8 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "activesupport", "~> 6.0.0"
-gem "concurrent-ruby", "1.3.4"
-
-gemspec path: "../"
diff --git a/gemfiles/rails_6.0.gemfile.lock b/gemfiles/rails_6.0.gemfile.lock
deleted file mode 100644
index b01c8f5..0000000
--- a/gemfiles/rails_6.0.gemfile.lock
+++ /dev/null
@@ -1,61 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    qbxml (0.5.0)
-      activesupport (>= 6.0.0)
-      bigdecimal
-      builder (~> 3.0)
-      nokogiri (~> 1.5)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activesupport (6.0.3.4)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 0.7, < 2)
-      minitest (~> 5.1)
-      tzinfo (~> 1.1)
-      zeitwerk (~> 2.2, >= 2.2.2)
-    appraisal (2.3.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
-    bigdecimal (3.2.1)
-    builder (3.3.0)
-    coderay (1.1.3)
-    concurrent-ruby (1.3.4)
-    i18n (1.8.5)
-      concurrent-ruby (~> 1.0)
-    method_source (0.9.2)
-    mini_portile2 (2.8.9)
-    minitest (5.14.2)
-    nokogiri (1.15.7)
-      mini_portile2 (~> 2.8.2)
-      racc (~> 1.4)
-    pry (0.12.2)
-      coderay (~> 1.1.0)
-      method_source (~> 0.9.0)
-    pry-nav (0.3.0)
-      pry (>= 0.9.10, < 0.13.0)
-    racc (1.8.1)
-    rake (13.0.1)
-    thor (1.0.1)
-    thread_safe (0.3.6)
-    tzinfo (1.2.8)
-      thread_safe (~> 0.1)
-    zeitwerk (2.4.2)
-
-PLATFORMS
-  ruby
-
-DEPENDENCIES
-  activesupport (~> 6.0.0)
-  appraisal
-  concurrent-ruby (= 1.3.4)
-  pry
-  pry-nav
-  qbxml!
-  rake
-
-BUNDLED WITH
-   2.1.4
diff --git a/gemfiles/rails_6.1.gemfile b/gemfiles/rails_6.1.gemfile
deleted file mode 100644
index 366d5df..0000000
--- a/gemfiles/rails_6.1.gemfile
+++ /dev/null
@@ -1,8 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "activesupport", "~> 6.1.0"
-gem "concurrent-ruby", "1.3.4"
-
-gemspec path: "../"
diff --git a/gemfiles/rails_6.1.gemfile.lock b/gemfiles/rails_6.1.gemfile.lock
deleted file mode 100644
index 033944c..0000000
--- a/gemfiles/rails_6.1.gemfile.lock
+++ /dev/null
@@ -1,58 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    qbxml (0.5.0)
-      activesupport (>= 6.0.0)
-      bigdecimal
-      builder (~> 3.0)
-      nokogiri (~> 1.5)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activesupport (6.1.0)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
-      zeitwerk (~> 2.3)
-    appraisal (2.3.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
-    bigdecimal (3.2.1)
-    builder (3.2.4)
-    coderay (1.1.3)
-    concurrent-ruby (1.3.4)
-    i18n (1.8.5)
-      concurrent-ruby (~> 1.0)
-    method_source (0.9.2)
-    minitest (5.14.2)
-    nokogiri (1.15.7-x86_64-linux)
-      racc (~> 1.4)
-    pry (0.12.2)
-      coderay (~> 1.1.0)
-      method_source (~> 0.9.0)
-    pry-nav (0.3.0)
-      pry (>= 0.9.10, < 0.13.0)
-    racc (1.8.1)
-    rake (13.0.1)
-    thor (1.0.1)
-    tzinfo (2.0.3)
-      concurrent-ruby (~> 1.0)
-    zeitwerk (2.4.2)
-
-PLATFORMS
-  x86_64-linux
-
-DEPENDENCIES
-  activesupport (~> 6.1.0)
-  appraisal
-  concurrent-ruby (= 1.3.4)
-  pry
-  pry-nav
-  qbxml!
-  rake
-
-BUNDLED WITH
-   2.3.27
diff --git a/gemfiles/rails_7.0.gemfile b/gemfiles/rails_7.0.gemfile
deleted file mode 100644
index 70ce46c..0000000
--- a/gemfiles/rails_7.0.gemfile
+++ /dev/null
@@ -1,8 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "activesupport", "~> 7.0.0"
-gem "concurrent-ruby", "1.3.4"
-
-gemspec path: "../"
diff --git a/gemfiles/rails_7.0.gemfile.lock b/gemfiles/rails_7.0.gemfile.lock
deleted file mode 100644
index 7f042a4..0000000
--- a/gemfiles/rails_7.0.gemfile.lock
+++ /dev/null
@@ -1,56 +0,0 @@
-PATH
-  remote: ..
-  specs:
-    qbxml (0.5.0)
-      activesupport (>= 6.0.0)
-      bigdecimal
-      builder (~> 3.0)
-      nokogiri (~> 1.5)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    activesupport (7.0.8.7)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
-    appraisal (2.5.0)
-      bundler
-      rake
-      thor (>= 0.14.0)
-    bigdecimal (3.2.1)
-    builder (3.3.0)
-    coderay (1.1.3)
-    concurrent-ruby (1.3.4)
-    i18n (1.14.7)
-      concurrent-ruby (~> 1.0)
-    method_source (1.1.0)
-    minitest (5.25.5)
-    nokogiri (1.15.7-x86_64-linux)
-      racc (~> 1.4)
-    pry (0.14.2)
-      coderay (~> 1.1)
-      method_source (~> 1.0)
-    pry-nav (1.0.0)
-      pry (>= 0.9.10, < 0.15)
-    racc (1.8.1)
-    rake (13.3.0)
-    thor (1.3.2)
-    tzinfo (2.0.6)
-      concurrent-ruby (~> 1.0)
-
-PLATFORMS
-  x86_64-linux
-
-DEPENDENCIES
-  activesupport (~> 7.0.0)
-  appraisal
-  concurrent-ruby (= 1.3.4)
-  pry
-  pry-nav
-  qbxml!
-  rake
-
-BUNDLED WITH
-   2.3.27
diff --git a/gemfiles/rails_7.1.gemfile.lock b/gemfiles/rails_7.1.gemfile.lock
index 7d6aab6..a94cac6 100644
--- a/gemfiles/rails_7.1.gemfile.lock
+++ b/gemfiles/rails_7.1.gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: ..
   specs:
     qbxml (0.5.0)
-      activesupport (>= 6.0.0)
+      activesupport (>= 7.1.0)
       bigdecimal
       builder (~> 3.0)
       nokogiri (~> 1.5)
@@ -10,7 +10,7 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (7.1.5.1)
+    activesupport (7.1.6)
       base64
       benchmark (>= 0.3)
       bigdecimal
@@ -28,37 +28,59 @@ GEM
       rake
       thor (>= 0.14.0)
     base64 (0.3.0)
-    benchmark (0.4.1)
-    bigdecimal (3.2.1)
+    benchmark (0.5.0)
+    bigdecimal (4.0.1)
     builder (3.3.0)
     coderay (1.1.3)
-    concurrent-ruby (1.3.5)
-    connection_pool (2.5.3)
+    concurrent-ruby (1.3.6)
+    connection_pool (3.0.2)
     drb (2.2.3)
-    i18n (1.14.7)
+    i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
     method_source (1.1.0)
-    mini_portile2 (2.8.9)
-    minitest (5.25.5)
+    minitest (6.0.2)
+      drb (~> 2.0)
+      prism (~> 1.5)
     mutex_m (0.3.0)
-    nokogiri (1.17.2)
-      mini_portile2 (~> 2.8.2)
+    nokogiri (1.19.1-aarch64-linux-gnu)
       racc (~> 1.4)
+    nokogiri (1.19.1-aarch64-linux-musl)
+      racc (~> 1.4)
+    nokogiri (1.19.1-arm-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.1-arm-linux-musl)
+      racc (~> 1.4)
+    nokogiri (1.19.1-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.1-x86_64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.1-x86_64-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.1-x86_64-linux-musl)
+      racc (~> 1.4)
+    prism (1.9.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
     pry-nav (1.0.0)
       pry (>= 0.9.10, < 0.15)
     racc (1.8.1)
-    rake (13.3.0)
-    securerandom (0.3.2)
-    thor (1.3.2)
+    rake (13.3.1)
+    securerandom (0.4.1)
+    thor (1.5.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
 
 PLATFORMS
-  ruby
+  aarch64-linux-gnu
+  aarch64-linux-musl
+  arm-linux-gnu
+  arm-linux-musl
+  arm64-darwin
+  x86_64-darwin
+  x86_64-linux-gnu
+  x86_64-linux-musl
 
 DEPENDENCIES
   activesupport (~> 7.1.0)
@@ -69,4 +91,4 @@ DEPENDENCIES
   rake
 
 BUNDLED WITH
-   2.3.27
+   2.6.9
diff --git a/gemfiles/rails_7.2.gemfile.lock b/gemfiles/rails_7.2.gemfile.lock
index ab08c95..23601db 100644
--- a/gemfiles/rails_7.2.gemfile.lock
+++ b/gemfiles/rails_7.2.gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: ..
   specs:
     qbxml (0.5.0)
-      activesupport (>= 6.0.0)
+      activesupport (>= 7.1.0)
       bigdecimal
       builder (~> 3.0)
       nokogiri (~> 1.5)
@@ -38,9 +38,12 @@ GEM
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
     method_source (1.1.0)
-    minitest (5.25.5)
-    nokogiri (1.18.8-x86_64-linux-gnu)
+    minitest (6.0.2)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    nokogiri (1.19.1-x86_64-linux-gnu)
       racc (~> 1.4)
+    prism (1.9.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
diff --git a/gemfiles/rails_8.0.gemfile.lock b/gemfiles/rails_8.0.gemfile.lock
index 6c5fa0c..16c2ee3 100644
--- a/gemfiles/rails_8.0.gemfile.lock
+++ b/gemfiles/rails_8.0.gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: ..
   specs:
     qbxml (0.5.0)
-      activesupport (>= 6.0.0)
+      activesupport (>= 7.1.0)
       bigdecimal
       builder (~> 3.0)
       nokogiri (~> 1.5)
@@ -39,23 +39,26 @@ GEM
       concurrent-ruby (~> 1.0)
     logger (1.7.0)
     method_source (1.1.0)
-    minitest (5.25.5)
-    nokogiri (1.18.8-aarch64-linux-gnu)
+    minitest (6.0.2)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    nokogiri (1.19.1-aarch64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.8-aarch64-linux-musl)
+    nokogiri (1.19.1-aarch64-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.18.8-arm-linux-gnu)
+    nokogiri (1.19.1-arm-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.8-arm-linux-musl)
+    nokogiri (1.19.1-arm-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.18.8-arm64-darwin)
+    nokogiri (1.19.1-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.18.8-x86_64-darwin)
+    nokogiri (1.19.1-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.18.8-x86_64-linux-gnu)
+    nokogiri (1.19.1-x86_64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.8-x86_64-linux-musl)
+    nokogiri (1.19.1-x86_64-linux-musl)
       racc (~> 1.4)
+    prism (1.9.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
diff --git a/gemfiles/rails_8.1.gemfile.lock b/gemfiles/rails_8.1.gemfile.lock
index c86f1f9..0d4ebdf 100644
--- a/gemfiles/rails_8.1.gemfile.lock
+++ b/gemfiles/rails_8.1.gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: ..
   specs:
     qbxml (0.5.0)
-      activesupport (>= 6.0.0)
+      activesupport (>= 7.1.0)
       bigdecimal
       builder (~> 3.0)
       nokogiri (~> 1.5)
@@ -39,23 +39,26 @@ GEM
     json (2.16.0)
     logger (1.7.0)
     method_source (1.1.0)
-    minitest (5.26.1)
-    nokogiri (1.18.10-aarch64-linux-gnu)
+    minitest (6.0.2)
+      drb (~> 2.0)
+      prism (~> 1.5)
+    nokogiri (1.19.1-aarch64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.10-aarch64-linux-musl)
+    nokogiri (1.19.1-aarch64-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.18.10-arm-linux-gnu)
+    nokogiri (1.19.1-arm-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.10-arm-linux-musl)
+    nokogiri (1.19.1-arm-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.18.10-arm64-darwin)
+    nokogiri (1.19.1-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.18.10-x86_64-darwin)
+    nokogiri (1.19.1-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.18.10-x86_64-linux-gnu)
+    nokogiri (1.19.1-x86_64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.18.10-x86_64-linux-musl)
+    nokogiri (1.19.1-x86_64-linux-musl)
       racc (~> 1.4)
+    prism (1.9.0)
     pry (0.14.2)
       coderay (~> 1.1)
       method_source (~> 1.0)
diff --git a/qbxml.gemspec b/qbxml.gemspec
index 5890008..f376c28 100644
--- a/qbxml.gemspec
+++ b/qbxml.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |gem|
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
 
-  gem.add_dependency('activesupport', '>= 6.0.0')
+  gem.add_dependency('activesupport', '>= 7.1.0')
   gem.add_dependency('nokogiri', '~> 1.5')
   gem.add_dependency('builder', '~> 3.0')
   gem.add_dependency('bigdecimal')