diff --git a/Gemfile b/Gemfile
index 1f15814..330ab8a 100755
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ ruby '~> 2'
 source 'https://rubygems.org/'
 
 gem 'combinatorics',  '~> 0.4.3'
-gem 'json', '~> 2.1.0'
+gem 'json', '~> 2.3.0'
 gem 'openssl', '~> 2'
 
 group :development do
@@ -12,5 +12,5 @@ group :development do
   gem 'rspec',          '~> 3.6'
   gem 'yard',           '~> 0.9.12'
   gem 'base16',         '~> 0.0.2'
-  gem 'simplecov',      '~> 0.7', :require => false
+  gem 'simplecov', '~> 0.14', '>= 0.14.1', :require => false
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index e013b6f..1d2ff7e 100755
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,10 +1,11 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    base16 (0.0.2)
     combinatorics (0.4.3)
     diff-lcs (1.3)
-    docile (1.1.5)
-    json (2.1.0)
+    docile (1.3.2)
+    json (2.3.0)
     openssl (2.0.3)
     rake (12.0.0)
     rspec (3.6.0)
@@ -21,28 +22,28 @@ GEM
       rspec-support (~> 3.6.0)
     rspec-support (3.6.0)
     rubygems-tasks (0.2.4)
-    simplecov (0.14.1)
-      docile (~> 1.1.0)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.1)
+    simplecov (0.18.5)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+    simplecov-html (0.12.2)
     yard (0.9.12)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  base16 (~> 0.0.2)
   combinatorics (~> 0.4.3)
-  json (~> 2.1.0)
+  json (~> 2.3.0)
   openssl (~> 2)
   rake (~> 12.0)
   rspec (~> 3.6)
   rubygems-tasks (~> 0.2)
-  simplecov (~> 0.7)
+  simplecov (~> 0.14, >= 0.14.1)
   yard (~> 0.9.12)
 
 RUBY VERSION
    ruby 2.4.1p111
 
 BUNDLED WITH
-   1.16.1
+   1.17.3