diff --git a/jekyll-responsive-image.gemspec b/jekyll-responsive-image.gemspec
index e16e1e0..e8f0df5 100644
--- a/jekyll-responsive-image.gemspec
+++ b/jekyll-responsive-image.gemspec
@@ -22,6 +22,6 @@ Gem::Specification.new do |spec|
   spec.executables   = []
   spec.require_paths = ['lib']
 
-  spec.add_runtime_dependency 'jekyll', ['>= 2.0', "< 4.0"]
+  spec.add_runtime_dependency 'jekyll', ['>= 2.0', "< 5.0"]
   spec.add_runtime_dependency 'rmagick', ['>= 2.0', '< 3.0']
 end