diff --git a/rails-keyserver.gemspec b/rails-keyserver.gemspec
index 7eae3b7..781adea 100644
--- a/rails-keyserver.gemspec
+++ b/rails-keyserver.gemspec
@@ -37,7 +37,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "attr_encrypted"
   spec.add_dependency "gpgme"
   spec.add_dependency "mysql2", "~> 0.5"
-  spec.add_dependency "rails", "~> 5.1"
+  spec.add_dependency "rails", ">= 5.1"
   spec.add_dependency "rake"
   spec.add_development_dependency "sqlite3"
 end