diff --git a/Library/Homebrew/cask/.simplecov b/Library/Homebrew/cask/.simplecov
deleted file mode 100644
index e1a2a4001a..0000000000
--- a/Library/Homebrew/cask/.simplecov
+++ /dev/null
@@ -1,6 +0,0 @@
-SimpleCov.start do
-  add_filter 'lib/vendor/'
-  add_filter 'doc/'
-  add_filter 'spec/'
-  add_filter 'test/'
-end
diff --git a/Library/Homebrew/cask/.simplecov b/Library/Homebrew/cask/.simplecov
new file mode 120000
index 0000000000..d1b0452626
--- /dev/null
+++ b/Library/Homebrew/cask/.simplecov
@@ -0,0 +1 @@
+../test/.simplecov
\ No newline at end of file
diff --git a/Library/Homebrew/cask/Rakefile b/Library/Homebrew/cask/Rakefile
index 6a6f76e6f5..7a276b347b 100644
--- a/Library/Homebrew/cask/Rakefile
+++ b/Library/Homebrew/cask/Rakefile
@@ -1,4 +1,3 @@
-require "coveralls/rake/task"
 require "rake/testtask"
 require "rspec/core/rake_task"
 require "rubocop/rake_task"
@@ -20,16 +19,21 @@ namespace :test do
 
   desc "Run tests for minitest and RSpec with coverage"
   task :coverage do
-    ENV["COVERAGE"] = "1"
+    ENV["HOMEBREW_TESTS_COVERAGE"] = "1"
+
     Rake::Task[:test].invoke
+
+    if ENV["TRAVIS"]
+      require "coveralls/rake/task"
+      Coveralls::RakeTask.new
+      Rake::Task['coveralls:push'].invoke
+    end
   end
 end
 
 desc "Run tests for minitest and RSpec"
 task test: ["test:minitest", "test:rspec"]
 
-Coveralls::RakeTask.new
-
 RuboCop::RakeTask.new(:rubocop) do |t|
   t.options = ["--force-exclusion"]
 end
diff --git a/Library/Homebrew/cask/spec/spec_helper.rb b/Library/Homebrew/cask/spec/spec_helper.rb
index d197db9835..6bb13bdcf1 100644
--- a/Library/Homebrew/cask/spec/spec_helper.rb
+++ b/Library/Homebrew/cask/spec/spec_helper.rb
@@ -2,9 +2,9 @@ require "pathname"
 require "rspec/its"
 require "rspec/wait"
 
-if ENV["COVERAGE"]
-  require "coveralls"
-  Coveralls.wear_merged!
+if ENV["HOMEBREW_TESTS_COVERAGE"]
+  require "simplecov"
+  SimpleCov.command_name "test:cask:rspec"
 end
 
 project_root = Pathname.new(File.expand_path("../..", __FILE__))
diff --git a/Library/Homebrew/cask/test/test_helper.rb b/Library/Homebrew/cask/test/test_helper.rb
index 24c9795351..e4fd721703 100644
--- a/Library/Homebrew/cask/test/test_helper.rb
+++ b/Library/Homebrew/cask/test/test_helper.rb
@@ -2,9 +2,9 @@ require "bundler"
 require "bundler/setup"
 require "pathname"
 
-if ENV["COVERAGE"]
-  require "coveralls"
-  Coveralls.wear_merged!
+if ENV["HOMEBREW_TESTS_COVERAGE"]
+  require "simplecov"
+  SimpleCov.command_name "test:cask:minitest"
 end
 
 project_root = Pathname.new(File.expand_path("../..", __FILE__))
diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index 4052daac28..d35e763458 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -659,7 +659,9 @@ module Homebrew
         test "brew", "readall", "--syntax"
         if OS.mac?
           run_as_not_developer { test "brew", "tap", "caskroom/cask" }
-          test "brew", "cask-tests"
+          tests_args_cask = []
+          tests_args_cask << "--coverage" if ARGV.include?("--coverage")
+          test "brew", "cask-tests", *tests_args_cask
         end
 
         # TODO: try to fix this on Linux at some stage.
diff --git a/Library/Homebrew/test/.simplecov b/Library/Homebrew/test/.simplecov
old mode 100644
new mode 100755
index 3cbd539431..7b057e878c
--- a/Library/Homebrew/test/.simplecov
+++ b/Library/Homebrew/test/.simplecov
@@ -1,18 +1,16 @@
-# vim: filetype=ruby
+#!/usr/bin/env ruby
 
 SimpleCov.start do
-  tests_path = File.dirname(__FILE__)
-
-  minimum_coverage 40 unless ENV["HOMEBREW_TESTS_ONLY"]
-  coverage_dir File.expand_path("#{tests_path}/coverage")
-  root File.expand_path("#{tests_path}/..")
+  coverage_dir File.expand_path("../coverage", File.realpath(__FILE__))
+  root File.expand_path("../..", File.realpath(__FILE__))
 
   # We manage the result cache ourselves and the default of 10 minutes can be
   # too low (particularly on Travis CI), causing results from some integration
   # tests to be dropped. This causes random fluctuations in test coverage.
   merge_timeout 86400
 
-  add_filter "/Homebrew/cask/"
+  add_filter "/Homebrew/cask/spec/"
+  add_filter "/Homebrew/cask/test/"
   add_filter "/Homebrew/compat/"
   add_filter "/Homebrew/test/"
   add_filter "/Homebrew/vendor/"
@@ -33,6 +31,7 @@ SimpleCov.start do
 
   # Add groups and the proper project name to the output.
   project_name "Homebrew"
+  add_group "Cask", "/Homebrew/cask/"
   add_group "Commands", %w[/Homebrew/cmd/ /Homebrew/dev-cmd/]
   add_group "Extensions", "/Homebrew/extend/"
   add_group "OS", %w[/Homebrew/extend/os/ /Homebrew/os/]
@@ -44,10 +43,3 @@ SimpleCov.start do
     /Homebrew/test.rb
   ]
 end
-
-# Don't use Coveralls outside of CI, as it will override SimpleCov's default
-# formatter causing the `index.html` not to be written once all tests finish.
-if RUBY_VERSION.split(".").first.to_i >= 2 && !ENV["HOMEBREW_INTEGRATION_TEST"] && ENV["CI"]
-  require "coveralls"
-  Coveralls.wear!
-end