diff --git a/.travis.yml b/.travis.yml
index 46bb12f..6b99df2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -26,6 +26,7 @@ gemfile:
   - gemfiles/rails_5_1.gemfile
   - gemfiles/rails_4_2.gemfile
   - gemfiles/dalli2.gemfile
+  - gemfiles/redis_4.gemfile
   - gemfiles/connection_pool_dalli.gemfile
   - gemfiles/active_support_redis_cache_store.gemfile
   - gemfiles/active_support_redis_cache_store_pooled.gemfile
diff --git a/Appraisals b/Appraisals
index 2cabba7..1328254 100644
--- a/Appraisals
+++ b/Appraisals
@@ -40,6 +40,10 @@ appraise 'dalli2' do
   gem 'dalli', '~> 2.0'
 end
 
+appraise 'redis_4' do
+  gem 'redis', '~> 4.0'
+end
+
 appraise "connection_pool_dalli" do
   gem "connection_pool", "~> 2.2"
   gem "dalli", "~> 2.7"
diff --git a/gemfiles/redis_4.gemfile b/gemfiles/redis_4.gemfile
new file mode 100644
index 0000000..701e936
--- /dev/null
+++ b/gemfiles/redis_4.gemfile
@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "redis", "~> 4.0"
+
+gemspec path: "../"
diff --git a/spec/acceptance/stores/redis_spec.rb b/spec/acceptance/stores/redis_spec.rb
new file mode 100644
index 0000000..8524db6
--- /dev/null
+++ b/spec/acceptance/stores/redis_spec.rb
@@ -0,0 +1,40 @@
+require_relative "../../spec_helper"
+
+if defined?(::Redis)
+  require_relative "../../support/cache_store_helper"
+  require "timecop"
+
+  describe "Plain redis as a cache backend" do
+    before do
+      Rack::Attack.cache.store = Redis.new
+    end
+
+    after do
+      Rack::Attack.cache.store.flushdb
+    end
+
+    it_works_for_cache_backed_features
+
+    it "doesn't leak keys" do
+      Rack::Attack.throttle("by ip", limit: 1, period: 1) do |request|
+        request.ip
+      end
+
+      key = nil
+
+      # Freeze time during these statement to be sure that the key used by rack attack is the same
+      # we pre-calculate in local variable `key`
+      Timecop.freeze do
+        key = "rack::attack:#{Time.now.to_i}:by ip:1.2.3.4"
+
+        get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+      end
+
+      assert Rack::Attack.cache.store.get(key)
+
+      sleep 2.1
+
+      assert_nil Rack::Attack.cache.store.get(key)
+    end
+  end
+end