diff --git a/jekyll-commonmark-ghpages.gemspec b/jekyll-commonmark-ghpages.gemspec
index 995d7ff..eeda034 100644
--- a/jekyll-commonmark-ghpages.gemspec
+++ b/jekyll-commonmark-ghpages.gemspec
@@ -3,7 +3,7 @@
 Gem::Specification.new do |spec|
   spec.name          = "jekyll-commonmark-ghpages"
   spec.summary       = "CommonMark generator for Jekyll"
-  spec.version       = "0.5.0"
+  spec.version       = "0.5.1"
   spec.authors       = ["GitHub, Inc."]
   spec.email         = "support@github.com"
   spec.homepage      = "https://github.com/github/jekyll-commonmark-ghpages"
@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency "jekyll", "~> 3.9.0"
+  spec.add_runtime_dependency "jekyll", ">= 3.9", "< 4.0"
   spec.add_runtime_dependency "jekyll-commonmark", "~> 1.4.0"
   spec.add_runtime_dependency "commonmarker", ">= 0.23.7", "< 1.1.0"
   spec.add_runtime_dependency "rouge", ">= 2.0", "< 5.0"