diff --git a/.gitignore b/.gitignore
index 9106b2a..4ea5798 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@
 /pkg/
 /spec/reports/
 /tmp/
+Gemfile.lock
diff --git a/Gemfile b/Gemfile
index 526b161..e89f8fd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,5 +2,10 @@ source "https://rubygems.org"
 
 git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
-# Specify your gem's dependencies in tracer.gemspec
 gemspec
+
+group :development do
+  gem "bundler"
+  gem "rake"
+  gem "test-unit"
+end
diff --git a/tracer.gemspec b/tracer.gemspec
index a230933..9eab333 100644
--- a/tracer.gemspec
+++ b/tracer.gemspec
@@ -20,8 +20,4 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-
-  spec.add_development_dependency "bundler"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "test-unit"
 end