diff --git a/macbuild/build4mac_env.py b/macbuild/build4mac_env.py
index cac9623de..0faed651b 100755
--- a/macbuild/build4mac_env.py
+++ b/macbuild/build4mac_env.py
@@ -192,7 +192,7 @@ RubySequoia      = { 'exe':  '/System/Library/Frameworks/Ruby.framework/Versions
 #  install with 'sudo port install ruby33'
 # [Key Type Name] = 'MP33'
 Ruby33MacPorts  = { 'exe': '/opt/local/bin/ruby3.3',
-                    'inc': '/opt/local/include/ruby-3.3.8',
+                    'inc': '/opt/local/include/ruby-3.3.9',
                     'lib': '/opt/local/lib/libruby.3.3.dylib'
                   }