diff --git a/.gitignore b/.gitignore
index fa85fdbfbf..5651548b7f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,8 @@
 .yardoc
 # Mac OS X files
 .DS_Store
+# simplecov coverage data
+coverage
 data/meterpreter/ext_server_pivot.dll
 data/meterpreter/ext_server_pivot.x64.dll
 doc
diff --git a/Gemfile b/Gemfile
index 825f532450..77d2123dae 100755
--- a/Gemfile
+++ b/Gemfile
@@ -24,4 +24,7 @@ end
 group :test do
   # testing framework
   gem 'rspec'
+  # code coverage for tests
+  # any version newer than 0.5.4 gives an Encoding error when trying to read the source files.
+  gem 'simplecov', '0.5.4', :require => false
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 10894e9139..a1fddbd358 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -45,6 +45,10 @@ GEM
     rspec-expectations (2.11.3)
       diff-lcs (~> 1.1.3)
     rspec-mocks (2.11.3)
+    simplecov (0.5.4)
+      multi_json (~> 1.0.3)
+      simplecov-html (~> 0.5.3)
+    simplecov-html (0.5.3)
     slop (3.3.3)
     tzinfo (0.3.33)
     yard (0.8.2.1)
@@ -60,4 +64,5 @@ DEPENDENCIES
   rake
   redcarpet
   rspec
+  simplecov (= 0.5.4)
   yard
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f62338294f..6f8932bc27 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -8,6 +8,11 @@ root_pathname = spec_pathname.join('..').expand_path
 lib_pathname = root_pathname.join('lib')
 $LOAD_PATH.unshift(lib_pathname.to_s)
 
+# must be first require and started before any other requires so that it can measure coverage of all following required
+# code.  It is after the rubygems and bundler only because Bundler.setup supplies the LOAD_PATH to simplecov.
+require 'simplecov'
+SimpleCov.start
+
 require 'rspec/core'
 
 # Requires supporting ruby files with custom matchers and macros, etc,