diff --git a/.codeclimate.yml b/.codeclimate.yml
index c54f8b4..917d643 100644
--- a/.codeclimate.yml
+++ b/.codeclimate.yml
@@ -13,6 +13,6 @@ plugins:
     enabled: true
   rubocop:
     enabled: true
-    channel: rubocop-1-39-0
+    channel: rubocop-1-56-3
 exclude_patterns:
   - "spec/"
diff --git a/rggen-c-header.gemspec b/rggen-c-header.gemspec
index ac29396..88bd562 100644
--- a/rggen-c-header.gemspec
+++ b/rggen-c-header.gemspec
@@ -25,6 +25,4 @@ Gem::Specification.new do |spec|
   spec.files =
     `git ls-files lib LICENSE CODE_OF_CONDUCT.md README.md`.split($RS)
   spec.require_paths = ['lib']
-
-  spec.add_development_dependency 'bundler'
 end