diff --git a/xdr.gemspec b/xdr.gemspec
index fd76fcf..cd99db1 100644
--- a/xdr.gemspec
+++ b/xdr.gemspec
@@ -25,6 +25,6 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = ">= 2.4.0"
 
-  spec.add_dependency "activesupport", ">= 4.2", "< 8.0"
-  spec.add_dependency "activemodel", ">= 4.2", "< 8.0"
+  spec.add_dependency "activesupport", ">= 4.2", "< 9.0"
+  spec.add_dependency "activemodel", ">= 4.2", "< 9.0"
 end