diff --git a/Gemfile b/Gemfile
index 20e0f98..51491fa 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,21 +2,18 @@
 
 source "https://rubygems.org"
 
-# Specify your gem's dependencies in safe_memoize.gemspec
 gemspec
 
-gem "irb"
-gem "rake", "~> 13.0"
-
-gem "rspec", "~> 3.0"
-
-gem "standard", "~> 1.3"
-
-# Optional adapters (soft deps — not required at runtime)
-gem "concurrent-ruby", "~> 1.3", require: false
-
-# Benchmarking
-gem "benchmark-ips", "~> 2.13", require: false
-
-# Documentation
-gem "yard", "~> 0.9", require: false
+group :development do
+  gem "benchmark-ips", "~> 2.13", require: false
+  gem "concurrent-ruby", "~> 1.3", require: false
+  gem "irb"
+  gem "rake", "~> 13.0"
+  gem "standard", "~> 1.3"
+  gem "yard", "~> 0.9", require: false
+end
+
+group :test do
+  gem "rspec", "~> 3.0"
+  gem "simplecov", "~> 0.22", require: false
+end
diff --git a/safe_memoize.gemspec b/safe_memoize.gemspec
index c2b28ee..c326a1f 100644
--- a/safe_memoize.gemspec
+++ b/safe_memoize.gemspec
@@ -39,9 +39,4 @@ Gem::Specification.new do |spec|
   spec.bindir = "exe"
   spec.executables = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
-
-  spec.add_development_dependency "simplecov", "~> 0.22"
-
-  # For more information and examples about making a new gem, check out our
-  # guide at: https://bundler.io/guides/creating_gem.html
 end