diff --git a/Gemfile b/Gemfile
index 989a852dc..b12ce6301 100644
--- a/Gemfile
+++ b/Gemfile
@@ -245,6 +245,9 @@ group :development do
   gem "pry"
   gem "pry-debundle"
   gem "pry-byebug"
+
+  # test coverage
+  gem "simplecov", "0.10.0", require: false
 end
 
 group :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index a28e4a7c6..c2d569720 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -157,6 +157,7 @@ GEM
       http_parser.rb (~> 0.6)
       nokogiri (~> 1.6)
     diff-lcs (1.2.5)
+    docile (1.1.5)
     domain_name (0.5.24)
       unf (>= 0.0.5, < 1.0.0)
     eco (1.0.0)
@@ -657,6 +658,11 @@ GEM
     simple_captcha2 (0.3.4)
       rails (>= 4.1)
     simple_oauth (0.3.1)
+    simplecov (0.10.0)
+      docile (~> 1.1.0)
+      json (~> 1.8)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.0)
     sinatra (1.4.6)
       rack (~> 1.4)
       rack-protection (~> 1.4)
@@ -837,6 +843,7 @@ DEPENDENCIES
   sidekiq (= 3.3.4)
   sidetiq (= 0.6.3)
   simple_captcha2 (= 0.3.4)
+  simplecov (= 0.10.0)
   sinatra (= 1.4.6)
   sinon-rails (= 1.10.3)
   spring (= 1.3.5)