diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7ef6925..2fe621d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## {{ UNRELEASED_VERSION }} - [{{ UNRELEASED_DATE }}]({{ UNRELEASED_LINK }})
 
+* Updated all images to `gen4`
+
 ## v1.6.0 - [October 16, 2024](https://github.com/lando/pantheon/releases/tag/v1.6.0)
 
 * Fixed blocking `certs` issues [#261](https://github.com/lando/pantheon/issues/261) [#262](https://github.com/lando/pantheon/issues/262)
diff --git a/builders/pantheon-php.js b/builders/pantheon-php.js
index 30e2261..58bd0af 100644
--- a/builders/pantheon-php.js
+++ b/builders/pantheon-php.js
@@ -23,21 +23,21 @@ const loadScripts = options => {
 module.exports = {
   name: 'pantheon-php',
   parent: '_appserver',
-  config: {
-    gen3: ['7.2', '7.1', '7.0', '5.6'],
-    gen4: ['8.3', '8.2', '8.1', '8.0', '7.4', '7.3'],
+  defaults: {
+    generation: '4',
   },
-  builder: (parent, config) => class PantheonPhp extends LandoPhp.builder(parent, LandoPhp.config) {
+  builder: (parent, defaults) => class PantheonPhp extends LandoPhp.builder(parent, LandoPhp.config) {
     constructor(id, options = {}, factory) {
+      // rebase option on defaults
+      options = _.merge({}, defaults, options);
+
       // Normalize because 7.0/8.0 right away gets handled strangely by js-yaml
       if (options.php === '7' || options.php === 7) options.php = '7.0';
       if (options.php === '8' || options.php === 8) options.php = '8.0';
 
-      if (_.includes(config.gen3, options.php)) options.tag = '3';
-      if (_.includes(config.gen4, options.php)) options.tag = '4';
-
+      // main event
       options.version = options.php;
-      options.image = `devwithlando/pantheon-appserver:${options.php}-${options.tag}`;
+      options.image = `devwithlando/pantheon-appserver:${options.php}-${options.generation}`;
       options.via = 'nginx:1.25';
 
       // Add in the prepend.php