diff --git a/Gemfile b/Gemfile
index ffff6f24371..eab0ed0bfa5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -158,7 +158,6 @@ end
 
 group :test, :development do
   gem 'rspec'
-  gem 'mock_redis'
   gem 'listen', require: false
   gem 'certified', require: false
   gem 'fabrication', require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 0d2a0ec3b2d..8209a9a638e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -241,8 +241,6 @@ GEM
       ffi (~> 1.9)
     minitest (5.15.0)
     mocha (1.13.0)
-    mock_redis (0.29.0)
-      ruby2_keywords
     msgpack (1.4.5)
     multi_json (1.15.0)
     multi_xml (0.6.0)
@@ -556,7 +554,6 @@ DEPENDENCIES
   mini_suffix
   minitest
   mocha
-  mock_redis
   multi_json
   mustache
   nokogiri
diff --git a/spec/components/common_passwords/common_passwords_spec.rb b/spec/components/common_passwords/common_passwords_spec.rb
index c68620d6e9e..4533de82008 100644
--- a/spec/components/common_passwords/common_passwords_spec.rb
+++ b/spec/components/common_passwords/common_passwords_spec.rb
@@ -3,7 +3,6 @@
 require "rails_helper"
 
 describe CommonPasswords do
-
   it "the passwords file should exist" do
     expect(File.exist?(described_class::PASSWORD_FILE)).to eq(true)
   end
@@ -39,31 +38,25 @@ describe CommonPasswords do
   end
 
   describe '#password_list' do
+    before { Discourse.redis.flushdb }
+    after { Discourse.redis.flushdb }
+
     it "loads the passwords file if redis doesn't have it" do
-      mock_redis = mock("redis")
-      mock_redis.stubs(:exists).returns(false)
-      mock_redis.stubs(:scard).returns(0)
-      described_class.stubs(:redis).returns(mock_redis)
+      Discourse.redis.without_namespace.stubs(:scard).returns(0)
       described_class.expects(:load_passwords).returns(['password'])
       list = described_class.password_list
       expect(list).to respond_to(:include?)
     end
 
     it "doesn't load the passwords file if redis has it" do
-      mock_redis = mock("redis")
-      mock_redis.stubs(:exists).returns(true)
-      mock_redis.stubs(:scard).returns(10000)
-      described_class.stubs(:redis).returns(mock_redis)
+      Discourse.redis.without_namespace.stubs(:scard).returns(10000)
       described_class.expects(:load_passwords).never
       list = described_class.password_list
       expect(list).to respond_to(:include?)
     end
 
     it "loads the passwords file if redis has an empty list" do
-      mock_redis = mock("redis")
-      mock_redis.stubs(:exists).returns(true)
-      mock_redis.stubs(:scard).returns(0)
-      described_class.stubs(:redis).returns(mock_redis)
+      Discourse.redis.without_namespace.stubs(:scard).returns(0)
       described_class.expects(:load_passwords).returns(['password'])
       list = described_class.password_list
       expect(list).to respond_to(:include?)
@@ -72,7 +65,6 @@ describe CommonPasswords do
 
   context "missing password file" do
     it "tolerates it" do
-      described_class.stubs(:redis).returns(stub_everything(sismember: false, exists: false, scard: 0))
       File.stubs(:readlines).with(described_class::PASSWORD_FILE).raises(Errno::ENOENT)
       expect(described_class.common_password?("password")).to eq(false)
     end
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index ef6f87dc6e3..90cf2c176b2 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -99,16 +99,6 @@ ENV['DISCOURSE_DEV_ALLOW_ANON_TO_IMPERSONATE'] = '1'
 module TestSetup
   # This is run before each test and before each before_all block
   def self.test_setup(x = nil)
-    # TODO not sure about this, we could use a mock redis implementation here:
-    #   this gives us really clean "flush" semantics, however the side-effect is that
-    #   we are no longer using a clean redis implementation, a preferable solution may
-    #   be simply flushing before tests, trouble is that redis may be reused with dev
-    #   so that would mean the dev would act weird
-    #
-    #   perf benefit seems low (shaves 20 secs off a 4 minute test suite)
-    #
-    # Discourse.redis = DiscourseMockRedis.new
-
     RateLimiter.disable
     PostActionNotifier.disable
     SearchIndexer.disable
@@ -250,16 +240,6 @@ RSpec.configure do |config|
     end
   end
 
-  class DiscourseMockRedis < MockRedis
-    def without_namespace
-      self
-    end
-
-    def delete_prefixed(prefix)
-      keys("#{prefix}*").each { |k| del(k) }
-    end
-  end
-
   config.after :each do |x|
     if x.exception && ex = RspecErrorTracker.last_exception
       # magic in a cause if we have none