diff --git a/Gemfile b/Gemfile
index 6fde5899..153a501e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,6 @@ gem 'aruba', '~> 0.6', require: false
 gem 'rspec', '~> 3.0', require: false
 gem 'fivemat', '~> 1.3', require: false
 gem 'cucumber', '~> 1.3', require: false
-gem 'contracts', '~> 0.4', require: false
 
 # Optional middleman dependencies, included for tests
 gem 'haml', '>= 4.0.5', require: false
diff --git a/middleman-core/middleman-core.gemspec b/middleman-core/middleman-core.gemspec
index 3c8c40a0..acfabe73 100644
--- a/middleman-core/middleman-core.gemspec
+++ b/middleman-core/middleman-core.gemspec
@@ -47,4 +47,7 @@ Gem::Specification.new do |s|
   # Minify JS
   s.add_dependency('uglifier', ['~> 2.5'])
   s.add_dependency('execjs', ['~> 2.0'])
+
+  # Testings
+  s.add_development_dependency('contracts', ['~> 0.4'])
 end