diff --git a/middleman-core/middleman-core.gemspec b/middleman-core/middleman-core.gemspec
index fde0883c..d8f25c64 100644
--- a/middleman-core/middleman-core.gemspec
+++ b/middleman-core/middleman-core.gemspec
@@ -37,7 +37,7 @@ Gem::Specification.new do |s|
   s.add_dependency('listen', ['~> 3.0.0'])
 
   # Tests
-  s.add_dependency("capybara", ["~> 2.5.0"])
+  s.add_development_dependency("capybara", ["~> 2.5.0"])
 
   # i18n
   s.add_dependency('i18n', ['~> 0.7.0'])