diff --git a/jekyll-admin.gemspec b/jekyll-admin.gemspec
index 7feb37e2..a33feb87 100644
--- a/jekyll-admin.gemspec
+++ b/jekyll-admin.gemspec
@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version     = ">= 2.3.0"
   spec.required_rubygems_version = ">= 2.7.0"
 
-  spec.add_dependency "jekyll", ">= 3.7", "< 5.0"
-  spec.add_dependency "sinatra", ">= 1.4"
-  spec.add_dependency "sinatra-contrib", ">= 1.4"
+  spec.add_runtime_dependency "jekyll", ">= 3.7", "< 5.0"
+  spec.add_runtime_dependency "sinatra", "~> 4.0"
+  spec.add_runtime_dependency "sinatra-contrib", "~> 4.0"
 end