diff --git a/devcycle-ruby-server-sdk.gemspec b/devcycle-ruby-server-sdk.gemspec
index 2934fcf..51a4132 100644
--- a/devcycle-ruby-server-sdk.gemspec
+++ b/devcycle-ruby-server-sdk.gemspec
@@ -25,7 +25,7 @@ Gem::Specification.new do |s|
 
   s.add_runtime_dependency 'typhoeus', '~> 1.0', '>= 1.0.1'
   s.add_runtime_dependency 'wasmtime', '13.0.0'
-  s.add_runtime_dependency 'concurrent-ruby', '~> 1.2.0'
+  s.add_runtime_dependency 'concurrent-ruby', '>= 1.2', '< 1.4'
   s.add_runtime_dependency 'sorbet-runtime', '~> 0.5'
   s.add_runtime_dependency 'oj', '~> 3.0'
   s.add_runtime_dependency 'google-protobuf', '~> 3.22'