diff --git a/clickmeetings.gemspec b/clickmeetings.gemspec
index a0fabf2..d2e11a8 100644
--- a/clickmeetings.gemspec
+++ b/clickmeetings.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'simplecov-gem-profile'
   spec.add_development_dependency 'webmock', '~> 2'
-  spec.add_dependency 'activemodel', '>= 4.1', '< 7'
+  spec.add_dependency 'activemodel', '>= 6.1', '< 8'
   spec.add_dependency 'anyway_config', '>= 0.3'
   spec.add_dependency 'faraday', '>= 1.0', '< 3'
   spec.add_dependency 'faraday_middleware', '>= 1.0'
diff --git a/lib/clickmeetings.rb b/lib/clickmeetings.rb
index 150ad87..cc131c2 100644
--- a/lib/clickmeetings.rb
+++ b/lib/clickmeetings.rb
@@ -40,9 +40,7 @@ def self.with_client(client)
   end
 
   class ClientRegistry # :nodoc:
-    extend ActiveSupport::PerThreadRegistry
-
-    attr_accessor :client
+    thread_mattr_accessor :client
   end
 
   require 'clickmeetings/engine' if defined?(Rails)
diff --git a/lib/clickmeetings/storage.rb b/lib/clickmeetings/storage.rb
index dd940f0..0f80f33 100644
--- a/lib/clickmeetings/storage.rb
+++ b/lib/clickmeetings/storage.rb
@@ -1,10 +1,8 @@
-require 'active_support/per_thread_registry'
+require "active_support/core_ext/module/attribute_accessors_per_thread"
 
 module Clickmeetings
   class Storage
-    extend ActiveSupport::PerThreadRegistry
-
-    attr_accessor :cm_current_conference, :cm_current_locale, :cm_open_current_account,
+    thread_mattr_accessor :cm_current_conference, :cm_current_locale, :cm_open_current_account,
                   :cm_private_current_account
   end
 end