diff --git a/instrumentation/action_mailer/Gemfile b/instrumentation/action_mailer/Gemfile
index 2ededff74..c0f09e6f4 100644
--- a/instrumentation/action_mailer/Gemfile
+++ b/instrumentation/action_mailer/Gemfile
@@ -11,4 +11,7 @@ gemspec
 group :test do
   gem 'opentelemetry-instrumentation-base', path: '../base'
   gem 'opentelemetry-instrumentation-active_support', path: '../active_support'
+  # Add jar-dependencies gem only if the Ruby runtime is JRuby
+  # https://github.com/jruby/jruby/issues/7262
+  gem 'jar-dependencies', '0.4.1', platforms: :jruby
 end
diff --git a/instrumentation/active_model_serializers/CHANGELOG.md b/instrumentation/active_model_serializers/CHANGELOG.md
index d6843c0f4..a6fc0f7ca 100644
--- a/instrumentation/active_model_serializers/CHANGELOG.md
+++ b/instrumentation/active_model_serializers/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Release History: opentelemetry-instrumentation-active_model_serializers
 
+### v0.20.3 / 2024-12-04
+
+* FIXED: Use ActiveSupport::Notifications subscriber to serialize events.
+
 ### v0.20.2 / 2024-07-23
 
 * DOCS: Add cspell to CI
diff --git a/instrumentation/active_model_serializers/lib/opentelemetry/instrumentation/active_model_serializers/version.rb b/instrumentation/active_model_serializers/lib/opentelemetry/instrumentation/active_model_serializers/version.rb
index 85f4d84de..d0b95c470 100644
--- a/instrumentation/active_model_serializers/lib/opentelemetry/instrumentation/active_model_serializers/version.rb
+++ b/instrumentation/active_model_serializers/lib/opentelemetry/instrumentation/active_model_serializers/version.rb
@@ -7,7 +7,7 @@
 module OpenTelemetry
   module Instrumentation
     module ActiveModelSerializers
-      VERSION = '0.20.2'
+      VERSION = '0.20.3'
     end
   end
 end