diff --git a/packages/compat/src/v1-config.ts b/packages/compat/src/v1-config.ts
index e9c52e4ed..62d5ae3ac 100644
--- a/packages/compat/src/v1-config.ts
+++ b/packages/compat/src/v1-config.ts
@@ -42,16 +42,20 @@ export class WriteV1Config extends Plugin {
     if (this.storeConfigInMeta) {
       contents = metaLoader();
     } else {
-      contents = `
-      import { isTesting } from '@embroider/macros';
-      let env;
-      if (isTesting()) {
-        env = ${JSON.stringify(this.testInputTree?.readConfig())};
+      if (this.testInputTree) {
+        contents = `
+        import { isTesting } from '@embroider/macros';
+        let env;
+        if (isTesting()) {
+          env = ${JSON.stringify(this.testInputTree.readConfig())};
+        } else {
+          env = ${JSON.stringify(this.inputTree.readConfig())};
+        }
+        export default env;
+        `;
       } else {
-        env = ${JSON.stringify(this.inputTree.readConfig())};
+        contents = `export default ${JSON.stringify(this.inputTree.readConfig())};`;
       }
-      export default env;
-      `;
     }
     if (!this.lastContents || this.lastContents !== contents) {
       outputFileSync(filename, contents);
diff --git a/tests/scenarios/app-config-environment-test.ts b/tests/scenarios/app-config-environment-test.ts
index 14e4f3fce..bbf76ca7e 100644
--- a/tests/scenarios/app-config-environment-test.ts
+++ b/tests/scenarios/app-config-environment-test.ts
@@ -44,10 +44,11 @@ appScenarios
             ENV.APP.LOG_VIEW_LOOKUPS = false;
             ENV.APP.rootElement = '#ember-testing';
             ENV.APP.autoboot = false;
+
+            // CUSTOM
+            ENV.someCustomField = true;
           };
 
-          // CUSTOM
-          ENV.someCustomField = true;
           return ENV;
         };`,
       },
@@ -57,7 +58,7 @@ appScenarios
             import { module, test } from 'qunit';
             import ENV from 'app-template/config/environment';
 
-            module('Unit | storeConfigInMeta', function (hooks) {
+            module('Unit | storeConfigInMeta set to false', function (hooks) {
               test('it has loaded the correct config values', async function (assert) {
                 assert.equal(ENV.someCustomField, true);
               });
@@ -73,9 +74,16 @@ appScenarios
         app = await scenario.prepare();
       });
 
-      test(`yarn test ran with custom unit test`, async function (assert) {
-        let result = await app.execute(`yarn test`);
-        assert.equal(result.exitCode, 0, result.output);
+      test(`ember test ran against dev build with custom unit test`, async function (assert) {
+        // here we build the app with environment set to dev so that we can use
+        // the build output directory as the input path to an `ember test` run
+        // later. This difference in environment is important because it's the
+        // only way for us to test ember-cli-build.js' `tests: true` behavior,
+        // and is equivalent to visiting the app's /tests page
+        let devBuildResult = await app.execute(`pnpm build --environment=development`);
+        assert.equal(devBuildResult.exitCode, 0, devBuildResult.output);
+        let testRunResult = await app.execute(`pnpm test:ember --path dist`);
+        assert.equal(testRunResult.exitCode, 0, testRunResult.output);
       });
     });
   });