diff --git a/.vscode/launch.json b/.vscode/launch.json
index 606b31feb..d79ade88e 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -59,7 +59,7 @@
     {
       // For this to work, make sure you're runninc `tsc --build --watch` at the root, AND
       // `yarn bundle:watch` from within vscode directory.
-      "name": "Debug Extension (TS Plugin Only)",
+      "name": "Debug Extension (TS Plugin, .gts)",
       "type": "extensionHost",
       "request": "launch",
       // "preLaunchTask": "npm: build",
@@ -71,10 +71,29 @@
       ],
       "args": [
         "--extensionDevelopmentPath=${workspaceFolder}/packages/vscode",
-        "--disable-extensions", // uncomment to activate your local extensions
+        "--disable-extensions", // comment to activate your local extensions
         "${workspaceFolder}/test-packages/ts-plugin-test-app"
       ]
     },
+    {
+      // For this to work, make sure you're runninc `tsc --build --watch` at the root, AND
+      // `yarn bundle:watch` from within vscode directory.
+      "name": "Debug Extension (TS Plugin, ember-app-loose-and-gts)",
+      "type": "extensionHost",
+      "request": "launch",
+      // "preLaunchTask": "npm: build",
+      "autoAttachChildProcesses": true,
+      "runtimeExecutable": "${execPath}",
+      "outFiles": [
+        "${workspaceFolder}/**/*.js",
+        "!**/node_modules/**"
+      ],
+      "args": [
+        "--extensionDevelopmentPath=${workspaceFolder}/packages/vscode",
+        "--disable-extensions", // comment to activate your local extensions
+        "${workspaceFolder}/packages/vscode/__fixtures__/ember-app-loose-and-gts/"
+      ]
+    },
     {
       "name": "Attach to TS Server",
       "type": "node",
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/app.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/app.ts
new file mode 100644
index 000000000..2c531e29a
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/app.ts
@@ -0,0 +1 @@
+import '@glint/environment-ember-loose';
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/Greeting.gts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/Greeting.gts
new file mode 100644
index 000000000..c919c8dac
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/Greeting.gts
@@ -0,0 +1,13 @@
+import Component from '@glimmer/component';
+
+export interface GreetingSignature {
+  Args: { target: string };
+}
+
+export default class Greeting extends Component<GreetingSignature> {
+  private message = 'Hello';
+
+  <template>
+    {{this.message}}, {{@target}}!
+  </template>
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.hbs
new file mode 100644
index 000000000..abe770add
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.hbs
@@ -0,0 +1,13 @@
+{{! This reference is correct; no errors }}
+{{this.message}}
+
+{{! This reference has a typo. Error expected }}
+{{this.messageeee}}
+
+{{!
+  If I reload VSCode via `Developer: Reload Window` (or fully restart the debugging session),
+  then the error diagnostics will be correctly calculated, but do not update/go away when I
+  fix the errors (and newly introduced errors do not show up).
+
+  Perhaps there is some TS Plugin caching issue with associated files?
+}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.ts
new file mode 100644
index 000000000..7b01b7fc1
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout-with-errors.ts
@@ -0,0 +1,5 @@
+import Component from '@glimmer/component';
+
+export default class ColocatedLayoutComponent extends Component {
+  private message = 'hello';
+}
diff --git a/packages/vscode/__fixtures__/ember-app/app/templates/components/classic-layout.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout.hbs
similarity index 100%
rename from packages/vscode/__fixtures__/ember-app/app/templates/components/classic-layout.hbs
rename to packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout.hbs
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout.ts
new file mode 100644
index 000000000..7b01b7fc1
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/colocated-layout.ts
@@ -0,0 +1,5 @@
+import Component from '@glimmer/component';
+
+export default class ColocatedLayoutComponent extends Component {
+  private message = 'hello';
+}
diff --git a/packages/vscode/__fixtures__/ember-app/app/components/classic-layout.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/component.ts
similarity index 54%
rename from packages/vscode/__fixtures__/ember-app/app/components/classic-layout.ts
rename to packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/component.ts
index 54088fe40..f7f7ed7db 100644
--- a/packages/vscode/__fixtures__/ember-app/app/components/classic-layout.ts
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/component.ts
@@ -1,5 +1,5 @@
 import Component from '@glimmer/component';
 
-export default class ClassicLayoutComponent extends Component {
+export default class PodLayoutComponent extends Component {
   private message = 'hello';
 }
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/template.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/template.hbs
new file mode 100644
index 000000000..07e73bb0b
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/pod-layout/template.hbs
@@ -0,0 +1 @@
+{{this.message}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/template-only.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/template-only.hbs
new file mode 100644
index 000000000..0710d87e4
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/components/template-only.hbs
@@ -0,0 +1 @@
+{{@foo}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/controllers/classic-controller-route.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/controllers/classic-controller-route.ts
new file mode 100644
index 000000000..24b533d83
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/controllers/classic-controller-route.ts
@@ -0,0 +1,5 @@
+import Controller from '@ember/controller';
+
+export default class PodController extends Controller {
+  declare model: { message: string };
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/controller.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/controller.ts
new file mode 100644
index 000000000..f1db7b31c
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/controller.ts
@@ -0,0 +1,5 @@
+import Controller from '@ember/controller';
+
+export default class ClassicController extends Controller {
+  declare model: { message: string };
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/route.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/route.ts
new file mode 100644
index 000000000..5e12710ba
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/route.ts
@@ -0,0 +1,7 @@
+import Route from '@ember/routing/route';
+
+export default class PodControllerRoute extends Route {
+  async model(): Promise<{ message: string }> {
+    return { message: 'hello' };
+  }
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/template.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/template.hbs
new file mode 100644
index 000000000..6bc86217b
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-controller-route/template.hbs
@@ -0,0 +1 @@
+{{@model.message}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/route.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/route.ts
new file mode 100644
index 000000000..6b674d221
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/route.ts
@@ -0,0 +1,7 @@
+import Route from '@ember/routing/route';
+
+export default class PodLoneRoute extends Route {
+  async model(): Promise<{ message: string }> {
+    return { message: 'hello' };
+  }
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/template.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/template.hbs
new file mode 100644
index 000000000..6bc86217b
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/pods/pod-lone-route/template.hbs
@@ -0,0 +1 @@
+{{@model.message}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-controller-route.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-controller-route.ts
new file mode 100644
index 000000000..6c47d2f49
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-controller-route.ts
@@ -0,0 +1,3 @@
+import Route from '@ember/routing/route';
+
+export default class ClassicControllerRoute extends Route {}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-lone-route.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-lone-route.ts
new file mode 100644
index 000000000..390efbda9
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/routes/classic-lone-route.ts
@@ -0,0 +1,7 @@
+import Route from '@ember/routing/route';
+
+export default class ClassicLoneRoute extends Route {
+  async model(): Promise<{ message: string }> {
+    return { message: 'hello' };
+  }
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-controller-route.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-controller-route.hbs
new file mode 100644
index 000000000..6bc86217b
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-controller-route.hbs
@@ -0,0 +1 @@
+{{@model.message}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-lone-route.hbs b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-lone-route.hbs
new file mode 100644
index 000000000..6bc86217b
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/app/templates/classic-lone-route.hbs
@@ -0,0 +1 @@
+{{@model.message}}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/package.json b/packages/vscode/__fixtures__/ember-app-loose-and-gts/package.json
new file mode 100644
index 000000000..85f1051db
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "test-ember-app-loose-and-gts",
+  "private": true
+}
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/tests/integration/component-test.ts b/packages/vscode/__fixtures__/ember-app-loose-and-gts/tests/integration/component-test.ts
new file mode 100644
index 000000000..d30865b3f
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/tests/integration/component-test.ts
@@ -0,0 +1,23 @@
+import { module, test } from 'qunit';
+import { setupRenderingTest } from 'ember-qunit';
+import { render } from '@ember/test-helpers';
+import { hbs } from 'ember-cli-htmlbars';
+import 'qunit-dom';
+
+module('Integration | component test', function (hooks) {
+  setupRenderingTest(hooks);
+
+  interface MyTestContext {
+    message: string;
+  }
+
+  test('typechecking', async function (this: MyTestContext, assert) {
+    this.message = 'hi';
+
+    await render<MyTestContext>(hbs`
+      {{this.message}}
+    `);
+
+    assert.dom().hasText('message');
+  });
+});
diff --git a/packages/vscode/__fixtures__/ember-app-loose-and-gts/tsconfig.json b/packages/vscode/__fixtures__/ember-app-loose-and-gts/tsconfig.json
new file mode 100644
index 000000000..787fc5937
--- /dev/null
+++ b/packages/vscode/__fixtures__/ember-app-loose-and-gts/tsconfig.json
@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "es2019",
+    "module": "es2015",
+    "moduleResolution": "bundler",
+    "skipLibCheck": true
+  },
+  "glint": {
+    "environment": ["ember-loose", "ember-template-imports"],
+    "enableTsPlugin": true
+  }
+}
diff --git a/packages/vscode/__tests__/language-server-tests/smoketest-ember.test.ts b/packages/vscode/__tests__/language-server-tests/smoketest-ember.test.ts
index 7e22c6080..cc5f57e1e 100644
--- a/packages/vscode/__tests__/language-server-tests/smoketest-ember.test.ts
+++ b/packages/vscode/__tests__/language-server-tests/smoketest-ember.test.ts
@@ -86,25 +86,6 @@ describe.skip('Smoke test: Ember', () => {
   });
 
   describe('component layout', () => {
-    test('classic', async () => {
-      let scriptURI = Uri.file(`${rootDir}/app/components/classic-layout.ts`);
-      let templateURI = Uri.file(`${rootDir}/app/templates/components/classic-layout.hbs`);
-
-      await window.showTextDocument(templateURI);
-
-      await waitUntil(() => extensions.getExtension('typed-ember.glint-vscode')?.isActive);
-
-      let positions = (await commands.executeCommand(
-        'vscode.executeDefinitionProvider',
-        templateURI,
-        new Position(0, 11),
-      )) as Array<Location>;
-
-      expect(positions.length).toBe(1);
-      expect(positions[0].uri.fsPath).toEqual(scriptURI.fsPath);
-      expect(positions[0].range).toEqual(new Range(3, 10, 3, 17));
-    });
-
     test('colocated', async () => {
       let scriptURI = Uri.file(`${rootDir}/app/components/colocated-layout.ts`);
       let templateURI = Uri.file(`${rootDir}/app/components/colocated-layout.hbs`);