diff --git a/cyberarm_engine.gemspec b/cyberarm_engine.gemspec
index 8d3ecef..73f3b85 100644
--- a/cyberarm_engine.gemspec
+++ b/cyberarm_engine.gemspec
@@ -33,7 +33,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "gosu_more_drawables", "~> 0.3"
   # spec.add_dependency "ffi", :platforms => [:mswin, :mingw] # Required by Clipboard on Windows
 
-  spec.add_development_dependency "bundler", "~> 1.16"
+  spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "minitest", "~> 5.0"
   spec.add_development_dependency "rake", "~> 13.0"
 end