diff --git a/Gemfile b/Gemfile
index 7a3e82b..1f61a32 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,8 @@
 source 'https://rubygems.org'
 
-# Specify your gem's dependencies in zlib.gemspec
 gemspec
+
+gem "bundler"
+gem "test-unit"
+gem "rake"
+gem "rake-compiler"
diff --git a/zlib.gemspec b/zlib.gemspec
index ae1f241..714afcc 100644
--- a/zlib.gemspec
+++ b/zlib.gemspec
@@ -28,8 +28,4 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
   spec.extensions    = "ext/zlib/extconf.rb"
   spec.required_ruby_version = ">= 2.3.0"
-
-  spec.add_development_dependency "bundler"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "rake-compiler"
 end