diff --git a/resumable_upload.gemspec b/resumable_upload.gemspec
index f830ff1..3052fec 100644
--- a/resumable_upload.gemspec
+++ b/resumable_upload.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |s|
   s.files = Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.rdoc"]
   s.test_files = Dir["test/**/*"]
 
-  s.add_dependency "rails", "~> 4.0"
+  s.add_dependency "rails", ">= 4", "< 7"
   s.add_dependency "bson", "~> 3.1"
   s.add_dependency "fog", "~> 1.36"
   s.add_dependency "dotenv"