diff --git a/just-the-docs.gemspec b/just-the-docs.gemspec
index c527a54210973b286cc4c5dfe4c68c8994c9421a..b1ba7bc9fa46a82b4463564d7f12a2d80ea6a5b4 100644
--- a/just-the-docs.gemspec
+++ b/just-the-docs.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files -z`.split("\x0").select { |f| f.match(%r{^(assets|bin|_layouts|_includes|lib|Rakefile|_sass|LICENSE|README)}i) }
   spec.executables   << 'just-the-docs'
 
-  spec.add_development_dependency "bundler", "~> 2.1.4"
+  spec.add_development_dependency "bundler", "~> 2.3.5"
   spec.add_runtime_dependency "jekyll", ">= 3.8.5"
   spec.add_runtime_dependency "jekyll-seo-tag", "~> 2.0"
   spec.add_runtime_dependency "rake", ">= 12.3.1", "< 13.1.0"