diff --git a/Gemfile b/Gemfile
index d398f4a..5b3dd70 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 gemspec
 
-gem "rails"
+gem "rails", "~> 5.2.5"
 gem "puma"
 
 gem "minitest"
diff --git a/Gemfile.lock b/Gemfile.lock
index a460be8..9e66350 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,95 +2,73 @@ PATH
   remote: .
   specs:
     activeexperiment (0.1.1.alpha)
-      activesupport (>= 7.0.4)
+      activesupport (>= 5.0.0)
       globalid (>= 0.3.6)
 
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (7.0.4)
-      actionpack (= 7.0.4)
-      activesupport (= 7.0.4)
+    actioncable (5.2.8.1)
+      actionpack (= 5.2.8.1)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
-    actionmailbox (7.0.4)
-      actionpack (= 7.0.4)
-      activejob (= 7.0.4)
-      activerecord (= 7.0.4)
-      activestorage (= 7.0.4)
-      activesupport (= 7.0.4)
-      mail (>= 2.7.1)
-      net-imap
-      net-pop
-      net-smtp
-    actionmailer (7.0.4)
-      actionpack (= 7.0.4)
-      actionview (= 7.0.4)
-      activejob (= 7.0.4)
-      activesupport (= 7.0.4)
+    actionmailer (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      actionview (= 5.2.8.1)
+      activejob (= 5.2.8.1)
       mail (~> 2.5, >= 2.5.4)
-      net-imap
-      net-pop
-      net-smtp
       rails-dom-testing (~> 2.0)
-    actionpack (7.0.4)
-      actionview (= 7.0.4)
-      activesupport (= 7.0.4)
-      rack (~> 2.0, >= 2.2.0)
+    actionpack (5.2.8.1)
+      actionview (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
+      rack (~> 2.0, >= 2.0.8)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.2.0)
-    actiontext (7.0.4)
-      actionpack (= 7.0.4)
-      activerecord (= 7.0.4)
-      activestorage (= 7.0.4)
-      activesupport (= 7.0.4)
-      globalid (>= 0.6.0)
-      nokogiri (>= 1.8.5)
-    actionview (7.0.4)
-      activesupport (= 7.0.4)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionview (5.2.8.1)
+      activesupport (= 5.2.8.1)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.1, >= 1.2.0)
-    activejob (7.0.4)
-      activesupport (= 7.0.4)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.2.8.1)
+      activesupport (= 5.2.8.1)
       globalid (>= 0.3.6)
-    activemodel (7.0.4)
-      activesupport (= 7.0.4)
-    activerecord (7.0.4)
-      activemodel (= 7.0.4)
-      activesupport (= 7.0.4)
-    activestorage (7.0.4)
-      actionpack (= 7.0.4)
-      activejob (= 7.0.4)
-      activerecord (= 7.0.4)
-      activesupport (= 7.0.4)
-      marcel (~> 1.0)
-      mini_mime (>= 1.1.0)
-    activesupport (7.0.4)
+    activemodel (5.2.8.1)
+      activesupport (= 5.2.8.1)
+    activerecord (5.2.8.1)
+      activemodel (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
+      arel (>= 9.0)
+    activestorage (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      activerecord (= 5.2.8.1)
+      marcel (~> 1.0.0)
+    activesupport (5.2.8.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 1.6, < 2)
-      minitest (>= 5.1)
-      tzinfo (~> 2.0)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    arel (9.0.0)
     ast (2.4.2)
-    bootsnap (1.15.0)
+    bootsnap (1.16.0)
       msgpack (~> 1.2)
     builder (3.2.4)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.2.2)
     connection_pool (2.3.0)
     crass (1.0.6)
+    date (3.3.3)
     docile (1.4.0)
-    erubi (1.11.0)
-    globalid (1.0.0)
+    erubi (1.12.0)
+    globalid (1.1.0)
       activesupport (>= 5.0)
     i18n (1.12.0)
       concurrent-ruby (~> 1.0)
-    json (2.6.2)
-    loofah (2.19.0)
+    json (2.6.3)
+    loofah (2.19.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
-    mail (2.8.0)
+    mail (2.8.1)
       mini_mime (>= 0.1.1)
       net-imap
       net-pop
@@ -98,9 +76,10 @@ GEM
     marcel (1.0.2)
     method_source (1.0.0)
     mini_mime (1.1.2)
-    minitest (5.16.3)
-    msgpack (1.6.0)
-    net-imap (0.3.1)
+    minitest (5.18.0)
+    msgpack (1.6.1)
+    net-imap (0.3.4)
+      date
       net-protocol
     net-pop (0.1.2)
       net-protocol
@@ -109,109 +88,103 @@ GEM
     net-smtp (0.3.3)
       net-protocol
     nio4r (2.5.8)
-    nokogiri (1.13.10-arm64-darwin)
-      racc (~> 1.4)
-    nokogiri (1.13.10-x86_64-darwin)
+    nokogiri (1.14.2-x86_64-darwin)
       racc (~> 1.4)
     parallel (1.22.1)
-    parser (3.1.3.0)
+    parser (3.2.1.1)
       ast (~> 2.4.1)
-    psych (4.0.6)
+    psych (5.1.0)
       stringio
-    puma (6.0.0)
+    puma (6.1.1)
       nio4r (~> 2.0)
-    racc (1.6.1)
-    rack (2.2.4)
-    rack-test (2.0.2)
+    racc (1.6.2)
+    rack (2.2.6.4)
+    rack-test (2.1.0)
       rack (>= 1.3)
-    rails (7.0.4)
-      actioncable (= 7.0.4)
-      actionmailbox (= 7.0.4)
-      actionmailer (= 7.0.4)
-      actionpack (= 7.0.4)
-      actiontext (= 7.0.4)
-      actionview (= 7.0.4)
-      activejob (= 7.0.4)
-      activemodel (= 7.0.4)
-      activerecord (= 7.0.4)
-      activestorage (= 7.0.4)
-      activesupport (= 7.0.4)
-      bundler (>= 1.15.0)
-      railties (= 7.0.4)
+    rails (5.2.8.1)
+      actioncable (= 5.2.8.1)
+      actionmailer (= 5.2.8.1)
+      actionpack (= 5.2.8.1)
+      actionview (= 5.2.8.1)
+      activejob (= 5.2.8.1)
+      activemodel (= 5.2.8.1)
+      activerecord (= 5.2.8.1)
+      activestorage (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
+      bundler (>= 1.3.0)
+      railties (= 5.2.8.1)
+      sprockets-rails (>= 2.0.0)
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.4.3)
-      loofah (~> 2.3)
-    railties (7.0.4)
-      actionpack (= 7.0.4)
-      activesupport (= 7.0.4)
+    rails-html-sanitizer (1.5.0)
+      loofah (~> 2.19, >= 2.19.1)
+    railties (5.2.8.1)
+      actionpack (= 5.2.8.1)
+      activesupport (= 5.2.8.1)
       method_source
-      rake (>= 12.2)
-      thor (~> 1.0)
-      zeitwerk (~> 2.5)
+      rake (>= 0.8.7)
+      thor (>= 0.19.0, < 2.0)
     rainbow (3.1.1)
     rake (13.0.6)
-    rdoc (6.4.0)
+    rdoc (6.5.0)
       psych (>= 4.0.0)
-    redis (5.0.5)
+    redis (5.0.6)
       redis-client (>= 0.9.0)
-    redis-client (0.11.2)
+    redis-client (0.14.0)
       connection_pool
-    regexp_parser (2.6.1)
+    regexp_parser (2.7.0)
     rexml (3.2.5)
-    rubocop (1.39.0)
+    rubocop (1.48.1)
       json (~> 2.3)
       parallel (~> 1.10)
-      parser (>= 3.1.2.1)
+      parser (>= 3.2.0.0)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.23.0, < 2.0)
+      rubocop-ast (>= 1.26.0, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.24.0)
-      parser (>= 3.1.1.0)
-    rubocop-minitest (0.24.0)
-      rubocop (>= 0.90, < 2.0)
+      unicode-display_width (>= 2.4.0, < 3.0)
+    rubocop-ast (1.27.0)
+      parser (>= 3.2.1.0)
+    rubocop-minitest (0.29.0)
+      rubocop (>= 1.39, < 2.0)
     rubocop-packaging (0.5.2)
       rubocop (>= 1.33, < 2.0)
-    rubocop-performance (1.15.1)
+    rubocop-performance (1.16.0)
       rubocop (>= 1.7.0, < 2.0)
       rubocop-ast (>= 0.4.0)
-    rubocop-rails (2.17.3)
+    rubocop-rails (2.18.0)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.33.0, < 2.0)
-    ruby-progressbar (1.11.0)
-    simplecov (0.21.2)
+    ruby-progressbar (1.13.0)
+    simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    sprockets (4.1.1)
+    sprockets (4.2.0)
       concurrent-ruby (~> 1.0)
-      rack (> 1, < 3)
+      rack (>= 2.2.4, < 4)
     sprockets-rails (3.4.2)
       actionpack (>= 5.2)
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
-    sqlite3 (1.5.4-arm64-darwin)
-    sqlite3 (1.5.4-x86_64-darwin)
-    stringio (3.0.2)
+    sqlite3 (1.6.1-x86_64-darwin)
+    stringio (3.0.5)
     thor (1.2.1)
-    timeout (0.3.1)
-    tzinfo (2.0.5)
-      concurrent-ruby (~> 1.0)
-    unicode-display_width (2.3.0)
+    thread_safe (0.3.6)
+    timeout (0.3.2)
+    tzinfo (1.2.11)
+      thread_safe (~> 0.1)
+    unicode-display_width (2.4.2)
     websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
-    zeitwerk (2.6.6)
 
 PLATFORMS
-  arm64-darwin-22
   x86_64-darwin-21
 
 DEPENDENCIES
@@ -219,7 +192,7 @@ DEPENDENCIES
   bootsnap
   minitest
   puma
-  rails
+  rails (~> 5.2.5)
   rdoc
   redis
   rubocop (>= 1.25.1)
@@ -232,4 +205,4 @@ DEPENDENCIES
   sqlite3 (~> 1.4)
 
 BUNDLED WITH
-   2.3.24
+   2.3.13
diff --git a/activeexperiment.gemspec b/activeexperiment.gemspec
index 4005ee3..bec0143 100644
--- a/activeexperiment.gemspec
+++ b/activeexperiment.gemspec
@@ -34,6 +34,6 @@ Gem::Specification.new do |s|
     "rubygems_mfa_required" => "true",
   }
 
-  s.add_dependency "activesupport", ">= 7.0.4" # TODO: use `version` here
+  s.add_dependency "activesupport", ">= 5.0.0" # TODO: use `version` here
   s.add_dependency "globalid", ">= 0.3.6"
 end
diff --git a/lib/active_experiment/core.rb b/lib/active_experiment/core.rb
index 1fddab6..8e74380 100644
--- a/lib/active_experiment/core.rb
+++ b/lib/active_experiment/core.rb
@@ -66,12 +66,12 @@ def experiment_name
       end
 
       private
-        def control(...)
-          variant(:control, ...)
+        def control(*filters, **options, &block)
+          variant(:control, *filters, **options, &block)
         end
 
-        def variant(name, ...)
-          register_variant_callback(name, ...)
+        def variant(name, *filters, **options, &block)
+          register_variant_callback(name, *filters, **options, &block)
         end
     end
 
diff --git a/lib/active_experiment/instrumentation.rb b/lib/active_experiment/instrumentation.rb
index 22b0ab5..2ef9999 100644
--- a/lib/active_experiment/instrumentation.rb
+++ b/lib/active_experiment/instrumentation.rb
@@ -26,6 +26,9 @@ def instrument(operation, **payload, &block)
         return ActiveSupport::Notifications.instrument(operation, payload) unless block.present?
 
         ActiveSupport::Notifications.instrument(operation, payload) do |event_payload|
+          @variant = nil unless defined?(@variant)
+          @halted_callback = nil unless defined?(@halted_callback)
+
           variant = @variant
           results = block.call
 
diff --git a/lib/active_experiment/rollouts/percent_rollout.rb b/lib/active_experiment/rollouts/percent_rollout.rb
index 927732b..afafaa7 100644
--- a/lib/active_experiment/rollouts/percent_rollout.rb
+++ b/lib/active_experiment/rollouts/percent_rollout.rb
@@ -35,7 +35,7 @@ module Rollouts
     #   ActiveExperiment::Base.default_rollout = :percent
     #   Rails.application.config.active_experiment.default_rollout = :percent
     class PercentRollout < BaseRollout
-      def initialize(experiment_class, ...) # :nodoc:
+      def initialize(experiment_class, *args, **options, &block) # :nodoc:
         super
 
         validate!(experiment_class)
diff --git a/lib/active_experiment/test_helper.rb b/lib/active_experiment/test_helper.rb
index 8701303..a433d8f 100644
--- a/lib/active_experiment/test_helper.rb
+++ b/lib/active_experiment/test_helper.rb
@@ -225,7 +225,7 @@ def assert_experiment_with(experiment_class, context: nil, options: nil, variant
     # stub out the rollout of an experiment in a test. It can also be inherited
     # and customized.
     class MockRollout < Rollouts::BaseRollout
-      def initialize(...)
+      def initialize(experiment_class, *args, **options, &block)
         @assigned = 0
         super
       end