diff --git a/packages/vscode/__tests__/ts-plugin-tests/smoketest-ember-app-loose-and-gts.test.ts b/packages/vscode/__tests__/ts-plugin-tests/smoketest-ember-app-loose-and-gts.test.ts
index 15828d4f6..e0167a82a 100644
--- a/packages/vscode/__tests__/ts-plugin-tests/smoketest-ember-app-loose-and-gts.test.ts
+++ b/packages/vscode/__tests__/ts-plugin-tests/smoketest-ember-app-loose-and-gts.test.ts
@@ -1,15 +1,4 @@
-import {
-  commands,
-  languages,
-  ViewColumn,
-  window,
-  Uri,
-  Range,
-  Position,
-  CodeAction,
-  workspace,
-  TextEditor,
-} from 'vscode';
+import { commands, languages, ViewColumn, window, Uri, Range } from 'vscode';
 import * as path from 'path';
 import { describe, afterEach, test } from 'mocha';
 import { expect } from 'expect';
@@ -28,15 +17,28 @@ describe('Smoke test: Loose Mode + GTS with TS Plugin Mode', () => {
   describe('loose mode aka ts + hbs two-file components', () => {
     describe('diagnostics', () => {
       test('reports errors and errors disappear when fixed', async () => {
-        let scriptURI = Uri.file(`${rootDir}/app/components/colocated-layout-with-errors.hbs`);
+        let tsScriptURI = Uri.file(`${rootDir}/app/components/colocated-layout-with-errors.ts`);
+
+        // Open the backing TS component file. Currently this is required in order to activate the VSCode,
+        // which is currently only configured to activate for .gts and .gjs files.
+        await window.showTextDocument(tsScriptURI, {
+          viewColumn: ViewColumn.One,
+        });
+
+        let hbsScriptURI = Uri.file(`${rootDir}/app/components/colocated-layout-with-errors.hbs`);
 
         // Open the script and the template
-        let scriptEditor = await window.showTextDocument(scriptURI, { viewColumn: ViewColumn.One });
+        let scriptEditor = await window.showTextDocument(hbsScriptURI, {
+          viewColumn: ViewColumn.One,
+        });
 
         // Wait for a diagnostic to appear in the template
-        await waitUntil(() => languages.getDiagnostics(scriptURI).length, 'diagnostic to appear');
+        await waitUntil(
+          () => languages.getDiagnostics(hbsScriptURI).length,
+          'diagnostic to appear',
+        );
 
-        expect(languages.getDiagnostics(scriptURI)).toMatchObject([
+        expect(languages.getDiagnostics(hbsScriptURI)).toMatchObject([
           {
             message:
               "Property 'messageeee' does not exist on type 'ColocatedLayoutComponent'. Did you mean 'message'?",
@@ -52,65 +54,10 @@ describe('Smoke test: Loose Mode + GTS with TS Plugin Mode', () => {
 
         // Wait for the diagnostic to disappear
         await waitUntil(
-          () => languages.getDiagnostics(scriptURI).length == 0,
+          () => languages.getDiagnostics(hbsScriptURI).length == 0,
           'diagnostic to disappear',
         );
       });
     });
   });
 });
-
-/**
- * It takes a little while for the TS Plugin to fully activate, and unfortunately
- * VSCode won't automatically re-trigger/re-calculate diagnostics for a file after
- * a TS Plugin kicks in, so we need some way to know that the TS Plugin is activated
- * before we edit the file.
- *
- * To accomplish this, this function inserts invalid TS into the .gts file and waits
- * for diagnostics to show up.
- */
-async function hackishlyWaitForTypescriptPluginToActivate(
-  scriptEditor: TextEditor,
-  scriptURI: Uri,
-): Promise<void> {
-  let invalidAssignment = 'let s: string = 123;';
-  await scriptEditor.edit((edit) => {
-    edit.insert(new Position(0, 0), invalidAssignment);
-  });
-
-  let numSpacesAdded = 0;
-  const startTime = Date.now();
-
-  // eslint-disable-next-line no-constant-condition
-  while (true) {
-    await scriptEditor.edit((edit) => {
-      edit.insert(new Position(0, 0), ' ');
-    });
-    numSpacesAdded++;
-
-    if (languages.getDiagnostics(scriptURI).length) {
-      break;
-    }
-
-    if (Date.now() - startTime > 5000) {
-      throw new Error(
-        'Timed out waiting for TS Plugin to activate (i.e. waiting for diagnostics to show up)',
-      );
-    }
-
-    // We'd love to wait for a smaller increment than 1000 but the editor
-    // debounces before triggering diagnostics so we need a large enough time.
-    await new Promise((resolve) => setTimeout(resolve, 1000));
-  }
-
-  // Remove our invalid assignment
-  await scriptEditor.edit((edit) => {
-    edit.replace(new Range(0, 0, 0, invalidAssignment.length + numSpacesAdded), '');
-  });
-
-  await new Promise((resolve) => setTimeout(resolve, 1000));
-
-  if (languages.getDiagnostics(scriptURI).length) {
-    throw new Error('Diagnostics still showing up after removing invalid assignment');
-  }
-}
diff --git a/packages/vscode/package.json b/packages/vscode/package.json
index 00b3b6585..df112c3ec 100644
--- a/packages/vscode/package.json
+++ b/packages/vscode/package.json
@@ -44,7 +44,10 @@
   "release-plan": {
     "skipNpmPublish": true
   },
-  "activationEvents": [],
+  "activationEvents": [
+    "onLanguage:glimmer-js",
+    "onLanguage:glimmer-ts"
+  ],
   "contributes": {
     "languages": [
       {