--- devise-two-factor.gemspec.orig	2017-10-06 09:46:06 UTC
+++ devise-two-factor.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
       s.add_runtime_dependency(%q<activesupport>.freeze, ["< 5.1"])
       s.add_runtime_dependency(%q<attr_encrypted>.freeze, ["!= 2", "< 4", ">= 1.3"])
       s.add_runtime_dependency(%q<devise>.freeze, ["~> 4.0"])
-      s.add_runtime_dependency(%q<rotp>.freeze, ["~> 2.0"])
+      s.add_runtime_dependency(%q<rotp>.freeze, [">= 2.0"])
       s.add_development_dependency(%q<activemodel>.freeze, [">= 0"])
       s.add_development_dependency(%q<appraisal>.freeze, [">= 0"])
       s.add_development_dependency(%q<bundler>.freeze, ["> 1.0"])