diff --git a/aws_security_viz.gemspec b/aws_security_viz.gemspec
index 12596b9..81a174f 100644
--- a/aws_security_viz.gemspec
+++ b/aws_security_viz.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
   end
   s.add_runtime_dependency 'rexml', '~> 3.2', '>= 3.2.2'
   s.add_runtime_dependency 'graphviz', '~> 1.1', '>= 1.1.0'
-  s.add_runtime_dependency 'optimist', '>= 3.0', '< 3.2'
+  s.add_runtime_dependency 'optimist', '>= 3.0', '< 3.3'
   s.add_runtime_dependency 'organic_hash', '~> 1.0', '>= 1.0.2'
   s.add_runtime_dependency 'rgl', '~> 0.5.3'
   s.add_runtime_dependency 'webrick', '~> 1.8.1'