diff --git a/google-api-client.gemspec b/google-api-client.gemspec
index e5e34980588..36e1da069f9 100644
--- a/google-api-client.gemspec
+++ b/google-api-client.gemspec
@@ -32,7 +32,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency 'extlib', '~> 0.9'
   s.add_runtime_dependency 'launchy', '~> 2.4'
   s.add_runtime_dependency 'retriable', '~> 1.4'
-  s.add_runtime_dependency 'activesupport', '>= 3.2', '< 5.0'
+  s.add_runtime_dependency 'activesupport', '>= 3.2', '< 6.0'
 
   s.add_development_dependency 'rake', '~> 10.0'
   s.add_development_dependency 'yard', '~> 0.8'