diff --git a/Gemfile.lock b/Gemfile.lock
index d0c252f3..fa9e2e6d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -15,22 +15,22 @@ GEM
   remote: https://rubygems.org/
   specs:
     RedCloth (4.3.4)
-    activesupport (7.2.3.1)
+    activesupport (8.1.3)
       base64
-      benchmark (>= 0.3)
       bigdecimal
       concurrent-ruby (~> 1.0, >= 1.3.1)
       connection_pool (>= 2.2.5)
       drb
       i18n (>= 1.6, < 2)
+      json
       logger (>= 1.4.2)
-      minitest (>= 5.1, < 6)
+      minitest (>= 5.1)
       securerandom (>= 0.3)
       tzinfo (~> 2.0, >= 2.0.5)
+      uri (>= 0.13.1)
     asciidoctor (2.0.26)
     base64 (0.3.0)
-    benchmark (0.5.0)
-    bigdecimal (4.1.0)
+    bigdecimal (4.1.2)
     builder (3.3.0)
     cgi (0.5.1)
     charlock_holmes (0.7.9)
@@ -52,6 +52,7 @@ GEM
     htmlentities (4.3.4)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
+    json (2.19.5)
     logger (1.7.0)
     mini_mime (1.1.5)
     mini_portile2 (2.8.9)
@@ -100,6 +101,7 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.9.1)
+    uri (1.1.1)
     wikicloth (0.8.3)
       builder
       expression_parser
@@ -117,7 +119,7 @@ PLATFORMS
 
 DEPENDENCIES
   RedCloth
-  activesupport (~> 7.2.3)
+  activesupport (~> 8.1.3)
   asciidoctor (~> 2.0.26)
   commonmarker!
   creole (~> 0.5.0)
diff --git a/github-markup.gemspec b/github-markup.gemspec
index 7a02478e..cea949c3 100644
--- a/github-markup.gemspec
+++ b/github-markup.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
   s.require_paths = %w[lib]
 
   s.add_development_dependency 'rake', '~> 13'
-  s.add_development_dependency 'activesupport', '~> 7.2.3'
+  s.add_development_dependency 'activesupport', '~> 8.1.3'
   s.add_development_dependency 'minitest', '~> 5.4', '>= 5.4.3'
   s.add_development_dependency 'html-pipeline', '~> 1.0'
   s.add_development_dependency 'sanitize', '>= 4.6.3'