diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 97ea165..3688977 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -278,6 +278,9 @@ importers:
       '@rollup/plugin-babel':
         specifier: ^6.1.0
         version: 6.1.0(@babel/core@7.29.0)(rollup@4.60.1)
+      babel-plugin-debug-macros:
+        specifier: ^0.3.4
+        version: 0.3.4(@babel/core@7.29.0)
       babel-plugin-ember-template-compilation:
         specifier: ^3.1.0
         version: 3.1.0
diff --git a/test-app/.try.mjs b/test-app/.try.mjs
index 085d877..a04a1d9 100644
--- a/test-app/.try.mjs
+++ b/test-app/.try.mjs
@@ -17,10 +17,10 @@ module.exports = async function (defaults) {
 };
 
   const ember4 = {
-    '@ember/test-helpers': '^4.0.0',
+    '@ember/test-helpers': '^5.0.0',
     '@ember/test-waiters': '^3.1.0',
     '@embroider/compat': '^4.0.3',
-    'ember-qunit': '^8.0.0',
+    'ember-qunit': '^9.0.0',
     'ember-cli': '~4.12.0',
   };
 
diff --git a/test-app/babel.config.mjs b/test-app/babel.config.mjs
index 441415c..7559820 100644
--- a/test-app/babel.config.mjs
+++ b/test-app/babel.config.mjs
@@ -4,6 +4,8 @@ import { buildMacros } from '@embroider/macros/babel';
 
 const macros = buildMacros();
 
+const isCompatBuild = !!process.env.ENABLE_COMPAT_BUILD;
+
 export default {
   plugins: [
     [
@@ -44,6 +46,16 @@ export default {
       },
     ],
     ...macros.babelMacros,
+    ...(isCompatBuild
+      ? [
+          [
+            'babel-plugin-debug-macros',
+            {
+              flags: [{ source: '@glimmer/env', flags: { DEBUG: true } }],
+            },
+          ],
+        ]
+      : []),
   ],
 
   generatorOpts: {
diff --git a/test-app/package.json b/test-app/package.json
index aa70314..ba31398 100644
--- a/test-app/package.json
+++ b/test-app/package.json
@@ -35,6 +35,7 @@
     "@babel/eslint-parser": "^7.23.3",
     "@babel/plugin-transform-runtime": "^7.29.0",
     "@babel/plugin-transform-typescript": "^7.28.6",
+    "babel-plugin-debug-macros": "^0.3.4",
     "@ember/string": "^4.0.1",
     "@ember/test-helpers": "^5.4.1",
     "@embroider/core": "^4.4.7",