diff --git a/swiss_bank_validator.gemspec b/swiss_bank_validator.gemspec
index b990856..dfe9984 100644
--- a/swiss_bank_validator.gemspec
+++ b/swiss_bank_validator.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
-  spec.add_dependency 'activemodel', '~> 6.0'
+  spec.add_dependency 'activemodel', '>= 6.0'
   spec.add_dependency 'rexml', '~> 3.2.5'
 
   spec.add_development_dependency 'rspec', '~> 3.0'