diff --git a/Appraisals b/Appraisals
index 9ca0281a..6114f5cc 100644
--- a/Appraisals
+++ b/Appraisals
@@ -42,26 +42,41 @@ end
 
 appraise "active_support_8-1_redis_cache_store" do
   gem "activesupport", "~> 8.1.0"
+  # Direct version requirement on connection_pool
+  # can be removed once https://github.com/rails/rails#56291 is fixed and released
+  gem "connection_pool", "~> 2.5"
   gem "redis", "~> 5.0"
 end
 
 appraise "active_support_8-0_redis_cache_store" do
   gem "activesupport", "~> 8.0.0"
+  # Direct version requirement on connection_pool
+  # can be removed once https://github.com/rails/rails#56291 is fixed and released
+  gem "connection_pool", "~> 2.5"
   gem "redis", "~> 5.0"
 end
 
 appraise "active_support_7-2_redis_cache_store" do
   gem "activesupport", "~> 7.2.0"
+  # Direct version requirement on connection_pool
+  # can be removed once https://github.com/rails/rails#56291 is fixed and released
+  gem "connection_pool", "~> 2.5"
   gem "redis", "~> 5.0"
 end
 
 appraise "active_support_7-1_redis_cache_store" do
   gem "activesupport", "~> 7.1.0"
+  # Direct version requirement on connection_pool
+  # can be removed once https://github.com/rails/rails#56291 is fixed and released
+  gem "connection_pool", "~> 2.5"
   gem "redis", "~> 5.0"
 end
 
 appraise "active_support_7-0_redis_cache_store" do
   gem "activesupport", "~> 7.0.0"
+  # Direct version requirement on connection_pool
+  # can be removed once https://github.com/rails/rails#56291 is fixed and released
+  gem "connection_pool", "~> 2.5"
   gem "redis", "~> 5.0"
 end
 
diff --git a/gemfiles/active_support_7_0_redis_cache_store.gemfile b/gemfiles/active_support_7_0_redis_cache_store.gemfile
index a94cfe88..f4e44cb7 100644
--- a/gemfiles/active_support_7_0_redis_cache_store.gemfile
+++ b/gemfiles/active_support_7_0_redis_cache_store.gemfile
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "activesupport", "~> 7.0.0"
+gem "connection_pool", "~> 2.5"
 gem "redis", "~> 5.0"
 
 group :maintenance, optional: true do
diff --git a/gemfiles/active_support_7_1_redis_cache_store.gemfile b/gemfiles/active_support_7_1_redis_cache_store.gemfile
index a0602ba5..f0b0ae68 100644
--- a/gemfiles/active_support_7_1_redis_cache_store.gemfile
+++ b/gemfiles/active_support_7_1_redis_cache_store.gemfile
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "activesupport", "~> 7.1.0"
+gem "connection_pool", "~> 2.5"
 gem "redis", "~> 5.0"
 
 group :maintenance, optional: true do
diff --git a/gemfiles/active_support_7_2_redis_cache_store.gemfile b/gemfiles/active_support_7_2_redis_cache_store.gemfile
index 3c433092..f0ec3a90 100644
--- a/gemfiles/active_support_7_2_redis_cache_store.gemfile
+++ b/gemfiles/active_support_7_2_redis_cache_store.gemfile
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "activesupport", "~> 7.2.0"
+gem "connection_pool", "~> 2.5"
 gem "redis", "~> 5.0"
 
 group :maintenance, optional: true do
diff --git a/gemfiles/active_support_8_0_redis_cache_store.gemfile b/gemfiles/active_support_8_0_redis_cache_store.gemfile
index b813cb38..e192fda3 100644
--- a/gemfiles/active_support_8_0_redis_cache_store.gemfile
+++ b/gemfiles/active_support_8_0_redis_cache_store.gemfile
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "activesupport", "~> 8.0.0"
+gem "connection_pool", "~> 2.5"
 gem "redis", "~> 5.0"
 
 group :maintenance, optional: true do
diff --git a/gemfiles/active_support_8_1_redis_cache_store.gemfile b/gemfiles/active_support_8_1_redis_cache_store.gemfile
index 57e0ff21..1dd14ed8 100644
--- a/gemfiles/active_support_8_1_redis_cache_store.gemfile
+++ b/gemfiles/active_support_8_1_redis_cache_store.gemfile
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "activesupport", "~> 8.1.0"
+gem "connection_pool", "~> 2.5"
 gem "redis", "~> 5.0"
 
 group :maintenance, optional: true do
diff --git a/rack-attack.gemspec b/rack-attack.gemspec
index 4d03a71b..03efa98a 100644
--- a/rack-attack.gemspec
+++ b/rack-attack.gemspec
@@ -44,9 +44,4 @@ Gem::Specification.new do |s|
   if RUBY_ENGINE == "ruby"
     s.add_development_dependency 'byebug', '~> 11.0'
   end
-
-  s.add_development_dependency "activesupport"
-  # Fix activesupport Direct version requirement on connection_pool
-  # can be removed once https://github.com/rails/rails/issues/56291 is ixed and released
-  s.add_development_dependency "connection_pool", "~> 2.5"
 end
diff --git a/spec/acceptance/allow2ban_spec.rb b/spec/acceptance/allow2ban_spec.rb
index 6de18d07..b4670ab8 100644
--- a/spec/acceptance/allow2ban_spec.rb
+++ b/spec/acceptance/allow2ban_spec.rb
@@ -5,7 +5,7 @@
 
 describe "allow2ban" do
   before do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
 
     Rack::Attack.blocklist("allow2ban pentesters") do |request|
       Rack::Attack::Allow2Ban.filter(request.ip, maxretry: 2, findtime: 30, bantime: 60) do
diff --git a/spec/acceptance/blocking_ip_spec.rb b/spec/acceptance/blocking_ip_spec.rb
index 4e41f29b..ff3d8dab 100644
--- a/spec/acceptance/blocking_ip_spec.rb
+++ b/spec/acceptance/blocking_ip_spec.rb
@@ -27,19 +27,21 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is blocked" do
-    ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is blocked" do
+      ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/blocking_spec.rb b/spec/acceptance/blocking_spec.rb
index 2ea9f67a..3e4e0846 100644
--- a/spec/acceptance/blocking_spec.rb
+++ b/spec/acceptance/blocking_spec.rb
@@ -23,21 +23,23 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is blocked" do
-    ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is blocked" do
+      ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_nil notification[:request].env["rack.attack.matched"]
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_nil notification[:request].env["rack.attack.matched"]
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
 
@@ -62,20 +64,22 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is blocked" do
-    ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is blocked" do
+      ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal "block 1.2.3.4", notification[:request].env["rack.attack.matched"]
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal "block 1.2.3.4", notification[:request].env["rack.attack.matched"]
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/blocking_subnet_spec.rb b/spec/acceptance/blocking_subnet_spec.rb
index 9fe30598..b89a17d7 100644
--- a/spec/acceptance/blocking_subnet_spec.rb
+++ b/spec/acceptance/blocking_subnet_spec.rb
@@ -27,19 +27,21 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is blocked" do
-    ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is blocked" do
+      ActiveSupport::Notifications.subscribe("blocklist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/cache_store_config_with_rails_spec.rb b/spec/acceptance/cache_store_config_with_rails_spec.rb
index 66bb76a8..23cb1046 100644
--- a/spec/acceptance/cache_store_config_with_rails_spec.rb
+++ b/spec/acceptance/cache_store_config_with_rails_spec.rb
@@ -4,32 +4,34 @@
 require "minitest/stub_const"
 require "ostruct"
 
-describe "Cache store config with Rails" do
-  before do
-    Rack::Attack.throttle("by ip", limit: 1, period: 60) do |request|
-      request.ip
+if defined?(::ActiveSupport::Cache::MemoryStore)
+  describe "Cache store config with Rails" do
+    before do
+      Rack::Attack.throttle("by ip", limit: 1, period: 60) do |request|
+        request.ip
+      end
     end
-  end
 
-  unless defined?(Rails)
-    it "fails when Rails.cache is not set" do
-      Object.stub_const(:Rails, OpenStruct.new(cache: nil)) do
-        assert_raises(Rack::Attack::MissingStoreError) do
-          get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+    unless defined?(Rails)
+      it "fails when Rails.cache is not set" do
+        Object.stub_const(:Rails, OpenStruct.new(cache: nil)) do
+          assert_raises(Rack::Attack::MissingStoreError) do
+            get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+          end
         end
       end
     end
-  end
 
-  it "works when Rails.cache is set" do
-    Object.stub_const(:Rails, OpenStruct.new(cache: ActiveSupport::Cache::MemoryStore.new)) do
-      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+    it "works when Rails.cache is set" do
+      Object.stub_const(:Rails, OpenStruct.new(cache: ActiveSupport::Cache::MemoryStore.new)) do
+        get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-      assert_equal 200, last_response.status
+        assert_equal 200, last_response.status
 
-      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+        get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-      assert_equal 429, last_response.status
+        assert_equal 429, last_response.status
+      end
     end
   end
 end
diff --git a/spec/acceptance/customizing_throttled_response_spec.rb b/spec/acceptance/customizing_throttled_response_spec.rb
index 0990975e..1f27adbd 100644
--- a/spec/acceptance/customizing_throttled_response_spec.rb
+++ b/spec/acceptance/customizing_throttled_response_spec.rb
@@ -4,7 +4,7 @@
 
 describe "Customizing throttled response" do
   before do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
 
     Rack::Attack.throttle("by ip", limit: 1, period: 60) do |request|
       request.ip
diff --git a/spec/acceptance/fail2ban_spec.rb b/spec/acceptance/fail2ban_spec.rb
index 74c01f57..7ebe5bec 100644
--- a/spec/acceptance/fail2ban_spec.rb
+++ b/spec/acceptance/fail2ban_spec.rb
@@ -7,7 +7,7 @@
   let(:notifications) { [] }
 
   before do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
 
     Rack::Attack.blocklist("fail2ban pentesters") do |request|
       Rack::Attack::Fail2Ban.filter(request.ip, maxretry: 2, findtime: 30, bantime: 60) do
@@ -78,43 +78,45 @@
     end
   end
 
-  it "notifies when the request is blocked" do
-    ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is blocked" do
+      ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/"
+      get "/"
 
-    assert_equal 200, last_response.status
-    assert notifications.empty?
+      assert_equal 200, last_response.status
+      assert notifications.empty?
 
-    get "/private-place"
+      get "/private-place"
 
-    assert_equal 403, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 403, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
 
-    get "/"
+      get "/"
 
-    assert_equal 200, last_response.status
-    assert notifications.empty?
+      assert_equal 200, last_response.status
+      assert notifications.empty?
 
-    get "/private-place"
+      get "/private-place"
 
-    assert_equal 403, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 403, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
 
-    get "/"
+      get "/"
 
-    assert_equal 403, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
-    assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 403, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal 'fail2ban pentesters', notification[:request].env["rack.attack.matched"]
+      assert_equal :blocklist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/safelisting_ip_spec.rb b/spec/acceptance/safelisting_ip_spec.rb
index e04ca6e5..fd7cc8ce 100644
--- a/spec/acceptance/safelisting_ip_spec.rb
+++ b/spec/acceptance/safelisting_ip_spec.rb
@@ -43,16 +43,18 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is safe" do
-    ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is safe" do
+      ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
+
+      get "/admin", {}, "REMOTE_ADDR" => "5.6.7.8"
+
+      assert_equal 200, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
     end
-
-    get "/admin", {}, "REMOTE_ADDR" => "5.6.7.8"
-
-    assert_equal 200, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
   end
 end
diff --git a/spec/acceptance/safelisting_spec.rb b/spec/acceptance/safelisting_spec.rb
index f00fada7..810b24d5 100644
--- a/spec/acceptance/safelisting_spec.rb
+++ b/spec/acceptance/safelisting_spec.rb
@@ -39,18 +39,20 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is safe" do
-    ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is safe" do
+      ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
+
+      get "/safe_space", {}, "REMOTE_ADDR" => "1.2.3.4"
+
+      assert_equal 200, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_nil notification[:request].env["rack.attack.matched"]
+      assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
     end
-
-    get "/safe_space", {}, "REMOTE_ADDR" => "1.2.3.4"
-
-    assert_equal 200, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_nil notification[:request].env["rack.attack.matched"]
-    assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
   end
 end
 
@@ -91,17 +93,19 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is safe" do
-    ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is safe" do
+      ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/safe_space", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/safe_space", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 200, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal "safe path", notification[:request].env["rack.attack.matched"]
-    assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
+      assert_equal 200, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal "safe path", notification[:request].env["rack.attack.matched"]
+      assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/safelisting_subnet_spec.rb b/spec/acceptance/safelisting_subnet_spec.rb
index baeb7e46..f56cb0cc 100644
--- a/spec/acceptance/safelisting_subnet_spec.rb
+++ b/spec/acceptance/safelisting_subnet_spec.rb
@@ -37,16 +37,18 @@
     assert_equal 200, last_response.status
   end
 
-  it "notifies when the request is safe" do
-    ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is safe" do
+      ActiveSupport::Notifications.subscribe("safelist.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
+
+      get "/admin", {}, "REMOTE_ADDR" => "5.6.0.0"
+
+      assert_equal 200, last_response.status
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
     end
-
-    get "/admin", {}, "REMOTE_ADDR" => "5.6.0.0"
-
-    assert_equal 200, last_response.status
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal :safelist, notification[:request].env["rack.attack.match_type"]
   end
 end
diff --git a/spec/acceptance/stores/active_support_mem_cache_store_spec.rb b/spec/acceptance/stores/active_support_mem_cache_store_spec.rb
index ccfe3db7..f997efc6 100644
--- a/spec/acceptance/stores/active_support_mem_cache_store_spec.rb
+++ b/spec/acceptance/stores/active_support_mem_cache_store_spec.rb
@@ -2,7 +2,7 @@
 
 require_relative "../../spec_helper"
 
-if defined?(::Dalli)
+if defined?(::Dalli) && defined?(::ActiveSupport::Cache::MemCacheStore)
   require_relative "../../support/cache_store_helper"
 
   describe "ActiveSupport::Cache::MemCacheStore as a cache backend" do
diff --git a/spec/acceptance/stores/active_support_memory_store_spec.rb b/spec/acceptance/stores/active_support_memory_store_spec.rb
index 4ed81e7f..4a219b82 100644
--- a/spec/acceptance/stores/active_support_memory_store_spec.rb
+++ b/spec/acceptance/stores/active_support_memory_store_spec.rb
@@ -1,16 +1,19 @@
 # frozen_string_literal: true
 
 require_relative "../../spec_helper"
-require_relative "../../support/cache_store_helper"
 
-describe "ActiveSupport::Cache::MemoryStore as a cache backend" do
-  before do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
-  end
+if defined?(::ActiveSupport::Cache::MemoryStore)
+  require_relative "../../support/cache_store_helper"
 
-  after do
-    Rack::Attack.cache.store.clear
-  end
+  describe "ActiveSupport::Cache::MemoryStore as a cache backend" do
+    before do
+      Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    end
 
-  it_works_for_cache_backed_features(fetch_from_store: ->(key) { Rack::Attack.cache.store.fetch(key) })
+    after do
+      Rack::Attack.cache.store.clear
+    end
+
+    it_works_for_cache_backed_features(fetch_from_store: ->(key) { Rack::Attack.cache.store.fetch(key) })
+  end
 end
diff --git a/spec/acceptance/stores/dalli_client_spec.rb b/spec/acceptance/stores/dalli_client_spec.rb
index 2b273740..f213a030 100644
--- a/spec/acceptance/stores/dalli_client_spec.rb
+++ b/spec/acceptance/stores/dalli_client_spec.rb
@@ -18,17 +18,19 @@
     it_works_for_cache_backed_features(fetch_from_store: ->(key) { Rack::Attack.cache.store.fetch(key) })
   end
 
-  describe "ConnectionPool with Dalli::Client as a cache backend" do
-    before do
-      Rack::Attack.cache.store = ConnectionPool.new { Dalli::Client.new }
+  if defined?(::ConnectionPool)
+    describe "ConnectionPool with Dalli::Client as a cache backend" do
+      before do
+        Rack::Attack.cache.store = ConnectionPool.new { Dalli::Client.new }
+      end
+
+      after do
+        Rack::Attack.cache.store.with { |client| client.flush_all }
+      end
+
+      it_works_for_cache_backed_features(
+        fetch_from_store: ->(key) { Rack::Attack.cache.store.with { |client| client.fetch(key) } }
+      )
     end
-
-    after do
-      Rack::Attack.cache.store.with { |client| client.flush_all }
-    end
-
-    it_works_for_cache_backed_features(
-      fetch_from_store: ->(key) { Rack::Attack.cache.store.with { |client| client.fetch(key) } }
-    )
   end
 end
diff --git a/spec/acceptance/throttling_spec.rb b/spec/acceptance/throttling_spec.rb
index ca81d1c5..475b2090 100644
--- a/spec/acceptance/throttling_spec.rb
+++ b/spec/acceptance/throttling_spec.rb
@@ -7,7 +7,7 @@
   let(:notifications) { [] }
 
   before do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
   end
 
   it "allows one request per minute by IP" do
@@ -135,36 +135,38 @@
     end
   end
 
-  it "notifies when the request is throttled" do
-    Rack::Attack.throttle("by ip", limit: 1, period: 60) do |request|
-      request.ip
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when the request is throttled" do
+      Rack::Attack.throttle("by ip", limit: 1, period: 60) do |request|
+        request.ip
+      end
 
-    ActiveSupport::Notifications.subscribe("throttle.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+      ActiveSupport::Notifications.subscribe("throttle.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert_equal 200, last_response.status
-    assert notifications.empty?
+      assert_equal 200, last_response.status
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 200, last_response.status
-    assert notifications.empty?
+      assert_equal 200, last_response.status
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 429, last_response.status
+      assert_equal 429, last_response.status
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal "by ip", notification[:request].env["rack.attack.matched"]
-    assert_equal :throttle, notification[:request].env["rack.attack.match_type"]
-    assert_equal 60, notification[:request].env["rack.attack.match_data"][:period]
-    assert_equal 1, notification[:request].env["rack.attack.match_data"][:limit]
-    assert_equal 2, notification[:request].env["rack.attack.match_data"][:count]
-    assert_equal "1.2.3.4", notification[:request].env["rack.attack.match_discriminator"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal "by ip", notification[:request].env["rack.attack.matched"]
+      assert_equal :throttle, notification[:request].env["rack.attack.match_type"]
+      assert_equal 60, notification[:request].env["rack.attack.match_data"][:period]
+      assert_equal 1, notification[:request].env["rack.attack.match_data"][:limit]
+      assert_equal 2, notification[:request].env["rack.attack.match_data"][:count]
+      assert_equal "1.2.3.4", notification[:request].env["rack.attack.match_discriminator"]
+    end
   end
 end
diff --git a/spec/acceptance/track_spec.rb b/spec/acceptance/track_spec.rb
index 62d1551a..bde2ad7e 100644
--- a/spec/acceptance/track_spec.rb
+++ b/spec/acceptance/track_spec.rb
@@ -5,24 +5,26 @@
 describe "#track" do
   let(:notifications) { [] }
 
-  it "notifies when track block returns true" do
-    Rack::Attack.track("ip 1.2.3.4") do |request|
-      request.ip == "1.2.3.4"
-    end
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when track block returns true" do
+      Rack::Attack.track("ip 1.2.3.4") do |request|
+        request.ip == "1.2.3.4"
+      end
 
-    ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+      ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal "ip 1.2.3.4", notification[:request].env["rack.attack.matched"]
-    assert_equal :track, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal "ip 1.2.3.4", notification[:request].env["rack.attack.matched"]
+      assert_equal :track, notification[:request].env["rack.attack.match_type"]
+    end
   end
 end
diff --git a/spec/acceptance/track_throttle_spec.rb b/spec/acceptance/track_throttle_spec.rb
index e6aa553a..ff64fc1f 100644
--- a/spec/acceptance/track_throttle_spec.rb
+++ b/spec/acceptance/track_throttle_spec.rb
@@ -6,44 +6,46 @@
 describe "#track with throttle-ish options" do
   let(:notifications) { [] }
 
-  it "notifies when throttle goes over the limit without actually throttling requests" do
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+  if defined?(::ActiveSupport::Notifications)
+    it "notifies when throttle goes over the limit without actually throttling requests" do
+      Rack::Attack.cache.store = SimpleMemoryStore.new
 
-    Rack::Attack.track("by ip", limit: 1, period: 60) do |request|
-      request.ip
-    end
+      Rack::Attack.track("by ip", limit: 1, period: 60) do |request|
+        request.ip
+      end
 
-    ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
-      notifications.push(payload)
-    end
+      ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
+        notifications.push(payload)
+      end
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    assert_equal 200, last_response.status
+      assert_equal 200, last_response.status
 
-    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+      get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
 
-    assert notifications.empty?
+      assert notifications.empty?
 
-    assert_equal 200, last_response.status
+      assert_equal 200, last_response.status
 
-    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-    assert_equal 1, notifications.size
-    notification = notifications.pop
-    assert_equal "by ip", notification[:request].env["rack.attack.matched"]
-    assert_equal :track, notification[:request].env["rack.attack.match_type"]
+      assert_equal 1, notifications.size
+      notification = notifications.pop
+      assert_equal "by ip", notification[:request].env["rack.attack.matched"]
+      assert_equal :track, notification[:request].env["rack.attack.match_type"]
 
-    assert_equal 200, last_response.status
+      assert_equal 200, last_response.status
 
-    Timecop.travel(60) do
-      get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      Timecop.travel(60) do
+        get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
 
-      assert notifications.empty?
+        assert notifications.empty?
 
-      assert_equal 200, last_response.status
+        assert_equal 200, last_response.status
+      end
     end
   end
 end
diff --git a/spec/allow2ban_spec.rb b/spec/allow2ban_spec.rb
index 105e0ad0..f0947d0b 100644
--- a/spec/allow2ban_spec.rb
+++ b/spec/allow2ban_spec.rb
@@ -8,7 +8,7 @@
     @cache = Rack::Attack.cache
     @findtime = 60
     @bantime  = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     @f2b_options = { bantime: @bantime, findtime: @findtime, maxretry: 2 }
 
     Rack::Attack.blocklist('pentest') do |req|
diff --git a/spec/fail2ban_spec.rb b/spec/fail2ban_spec.rb
index 6a9d9bcf..aeeea908 100644
--- a/spec/fail2ban_spec.rb
+++ b/spec/fail2ban_spec.rb
@@ -8,7 +8,7 @@
     @cache = Rack::Attack.cache
     @findtime = 60
     @bantime  = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     @f2b_options = { bantime: @bantime, findtime: @findtime, maxretry: 2 }
 
     Rack::Attack.blocklist('pentest') do |req|
diff --git a/spec/integration/offline_spec.rb b/spec/integration/offline_spec.rb
index 85429a42..c480d7e8 100644
--- a/spec/integration/offline_spec.rb
+++ b/spec/integration/offline_spec.rb
@@ -1,8 +1,13 @@
 # frozen_string_literal: true
 
-require 'active_support/cache'
 require_relative '../spec_helper'
 
+begin
+  require 'active_support/cache'
+rescue LoadError
+  # ActiveSupport is optional
+end
+
 OfflineExamples = Minitest::SharedExamples.new do
   it 'should write' do
     @cache.write('cache-test-key', 'foobar', 1)
diff --git a/spec/rack_attack_instrumentation_spec.rb b/spec/rack_attack_instrumentation_spec.rb
index d2291f77..cae13234 100644
--- a/spec/rack_attack_instrumentation_spec.rb
+++ b/spec/rack_attack_instrumentation_spec.rb
@@ -1,39 +1,41 @@
 # frozen_string_literal: true
 
 require_relative "spec_helper"
-require 'active_support'
-require 'active_support/subscriber'
 
-class CustomSubscriber < ActiveSupport::Subscriber
-  @notification_count = 0
+require 'active_support/subscriber'
+if defined?(::ActiveSupport::Subscriber)
 
-  class << self
-    attr_accessor :notification_count
-  end
+  class CustomSubscriber < ActiveSupport::Subscriber
+    @notification_count = 0
 
-  def throttle(_event)
-    self.class.notification_count += 1
-  end
-end
+    class << self
+      attr_accessor :notification_count
+    end
 
-describe 'Rack::Attack.instrument' do
-  before do
-    @period = 60 # Use a long period; failures due to cache key rotation less likely
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
-    Rack::Attack.throttle('ip/sec', limit: 1, period: @period) { |req| req.ip }
+    def throttle(_event)
+      self.class.notification_count += 1
+    end
   end
 
-  describe "with throttling" do
+  describe 'Rack::Attack.instrument' do
     before do
-      ActiveSupport::Notifications.stub(:notifier, ActiveSupport::Notifications::Fanout.new) do
-        CustomSubscriber.attach_to("rack_attack")
-        2.times { get '/', {}, 'REMOTE_ADDR' => '1.2.3.4' }
-      end
+      @period = 60 # Use a long period; failures due to cache key rotation less likely
+      Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+      Rack::Attack.throttle('ip/sec', limit: 1, period: @period) { |req| req.ip }
     end
 
-    it 'should instrument without error' do
-      _(last_response.status).must_equal 429
-      assert_equal 1, CustomSubscriber.notification_count
+    describe "with throttling" do
+      before do
+        ActiveSupport::Notifications.stub(:notifier, ActiveSupport::Notifications::Fanout.new) do
+          CustomSubscriber.attach_to("rack_attack")
+          2.times { get '/', {}, 'REMOTE_ADDR' => '1.2.3.4' }
+        end
+      end
+
+      it 'should instrument without error' do
+        _(last_response.status).must_equal 429
+        assert_equal 1, CustomSubscriber.notification_count
+      end
     end
   end
 end
diff --git a/spec/rack_attack_throttle_spec.rb b/spec/rack_attack_throttle_spec.rb
index 1bf7f32f..9cd0ab51 100644
--- a/spec/rack_attack_throttle_spec.rb
+++ b/spec/rack_attack_throttle_spec.rb
@@ -6,7 +6,7 @@
 describe 'Rack::Attack.throttle' do
   before do
     @period = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     Rack::Attack.throttle('ip/sec', limit: 1, period: @period) { |req| req.ip }
   end
 
@@ -70,7 +70,7 @@
 describe 'Rack::Attack.throttle with limit as proc' do
   before do
     @period = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     Rack::Attack.throttle('ip/sec', limit: lambda { |_req| 1 }, period: @period) { |req| req.ip }
   end
 
@@ -104,7 +104,7 @@
 describe 'Rack::Attack.throttle with period as proc' do
   before do
     @period = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     Rack::Attack.throttle('ip/sec', limit: lambda { |_req| 1 }, period: lambda { |_req| @period }) { |req| req.ip }
   end
 
@@ -139,7 +139,7 @@
 describe 'Rack::Attack.throttle with block returning nil' do
   before do
     @period = 60
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     Rack::Attack.throttle('ip/sec', limit: 1, period: @period) { |_| nil }
   end
 
@@ -170,7 +170,7 @@
       "PERSON@example.com ",
       " person@example.com\r\n  ",
     ]
-    Rack::Attack.cache.store = ActiveSupport::Cache::MemoryStore.new
+    Rack::Attack.cache.store = SimpleMemoryStore.new
     Rack::Attack.throttle('logins/email', limit: 4, period: @period) do |req|
       if req.path == '/login' && req.post?
         req.params['email']
diff --git a/spec/rack_attack_track_spec.rb b/spec/rack_attack_track_spec.rb
index 0013c15b..37f23dab 100644
--- a/spec/rack_attack_track_spec.rb
+++ b/spec/rack_attack_track_spec.rb
@@ -3,8 +3,6 @@
 require_relative 'spec_helper'
 
 describe 'Rack::Attack.track' do
-  let(:notifications) { [] }
-
   before do
     Rack::Attack.track("everything") { |_req| true }
   end
@@ -18,20 +16,24 @@
     _(last_request.env['rack.attack.match_type']).must_equal :track
   end
 
-  describe "with a notification subscriber and two tracks" do
-    before do
-      # A second track
-      Rack::Attack.track("homepage") { |req| req.path == "/" }
+  if defined?(::ActiveSupport::Notifications)
+    describe "with a notification subscriber and two tracks" do
+      let(:notifications) { [] }
 
-      ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
-        notifications.push(payload)
-      end
+      before do
+        # A second track
+        Rack::Attack.track("homepage") { |req| req.path == "/" }
 
-      get "/"
-    end
+        ActiveSupport::Notifications.subscribe("track.rack_attack") do |_name, _start, _finish, _id, payload|
+          notifications.push(payload)
+        end
 
-    it "should notify twice" do
-      _(notifications.size).must_equal 2
+        get "/"
+      end
+
+      it "should notify twice" do
+        _(notifications.size).must_equal 2
+      end
     end
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 894de6a1..ee17781f 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,22 +1,68 @@
 # frozen_string_literal: true
 
+def safe_require(name)
+  require name
+rescue LoadError
+  nil
+end
+
 require "bundler/setup"
 
 require "logger"
 require "minitest/autorun"
 require "minitest/pride"
 require "rack/test"
-require "active_support"
+safe_require "active_support"
 require "rack/attack"
 
-if RUBY_ENGINE == "ruby"
-  require "byebug"
+# Simple in-memory cache store for testing without ActiveSupport dependency
+class SimpleMemoryStore
+  def initialize
+    @data = {}
+  end
+
+  def read(key)
+    entry = @data[key]
+    return nil unless entry
+    return nil if entry[:expires_at] && entry[:expires_at] < Time.now
+
+    entry[:value]
+  end
+
+  def write(key, value, options = {})
+    expires_at = options[:expires_in] ? Time.now + options[:expires_in] : nil
+    @data[key] = { value: value, expires_at: expires_at }
+    true
+  end
+
+  def increment(key, amount = 1, options = {})
+    current = read(key)
+    if current.nil?
+      nil
+    else
+      new_value = current.to_i + amount
+      write(key, new_value, options)
+      new_value
+    end
+  end
+
+  def delete(key)
+    @data.delete(key)
+  end
+
+  def delete_matched(matcher)
+    @data.keys.each do |key|
+      @data.delete(key) if key.match?(matcher)
+    end
+  end
+
+  def clear
+    @data.clear
+  end
 end
 
-def safe_require(name)
-  require name
-rescue LoadError
-  nil
+if RUBY_ENGINE == "ruby"
+  require "byebug"
 end
 
 safe_require "connection_pool"