diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2fcd611..eed6d24 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## 3.4.0
+
+- Await pending `Meteor.startup()` callbacks before running tests, so async startup work (e.g. ensuring MongoDB indices) finishes before `mocha.run()` fires on Meteor 3.x. [PR #177](https://github.com/Meteor-Community-Packages/meteor-mocha/pull/177)
+
 ## 3.0.0
 
 - Meteor 3.0 compatibility; drop Fibers
diff --git a/package/.versions b/package/.versions
index b456b30..0e35f0b 100644
--- a/package/.versions
+++ b/package/.versions
@@ -1,19 +1,19 @@
-babel-compiler@7.11.3
+babel-compiler@7.14.1
 babel-runtime@1.5.2
 core-runtime@1.0.0
 dynamic-import@0.7.4
-ecmascript@0.16.10
+ecmascript@0.18.1
 ecmascript-runtime@0.8.3
-ecmascript-runtime-client@0.12.3
+ecmascript-runtime-client@0.13.0
 ecmascript-runtime-server@0.11.1
-fetch@0.1.6
+fetch@0.2.0
 inter-process-messaging@0.1.2
-meteor@2.1.0
+meteor@2.3.1
 meteortesting:browser-tests@1.8.0
-meteortesting:mocha@3.3.0
+meteortesting:mocha@3.4.0-rc.1
 meteortesting:mocha-core@8.3.1-rc300.1
-modern-browsers@0.2.1
+modern-browsers@0.2.3
 modules@0.20.3
 modules-runtime@0.13.2
 promise@1.0.0
-react-fast-refresh@0.2.9
+react-fast-refresh@0.3.0
diff --git a/package/package.js b/package/package.js
index be24c34..57f1455 100644
--- a/package/package.js
+++ b/package/package.js
@@ -3,7 +3,7 @@ Package.describe({
   summary: 'Run Meteor package or app tests with Mocha',
   git: 'https://github.com/meteortesting/meteor-mocha.git',
   documentation: '../README.md',
-  version: '3.3.0',
+  version: '3.4.0-rc.1',
   testOnly: true,
 });
 
diff --git a/package/server.js b/package/server.js
index 8439af4..4b100c8 100644
--- a/package/server.js
+++ b/package/server.js
@@ -203,8 +203,14 @@ function clientTests() {
   });
 }
 
-// Before Meteor calls the `start` function, app tests will be parsed and loaded by Mocha
+// Run tests from a new startup hook so every hook already queued, including
+// async ones, completes first. Awaiting a callback added to the startup queue
+// here would deadlock: this function itself is run by that queue.
 function start() {
+  Meteor.startup(runTests);
+}
+
+function runTests() {
   const args = setArgs();
   runnerOptions = args.runnerOptions;
   coverageOptions = args.coverageOptions;
diff --git a/tests/dummy_app/server/async-startup.tests.js b/tests/dummy_app/server/async-startup.tests.js
new file mode 100644
index 0000000..04fee7b
--- /dev/null
+++ b/tests/dummy_app/server/async-startup.tests.js
@@ -0,0 +1,21 @@
+/* eslint-env mocha */
+import { Meteor } from 'meteor/meteor';
+import assert from 'assert';
+
+// Simulate async startup work (e.g. ensuring MongoDB indices, initializing
+// collections). Without the fix in server.js, mocha.run() can fire before
+// this callback completes, causing the test below to fail.
+let startupCompleted = false;
+
+Meteor.startup(async () => {
+  await new Promise(resolve => setTimeout(resolve, 50));
+  startupCompleted = true;
+});
+
+describe('async Meteor.startup()', function () {
+  it('should complete before tests run', function () {
+    assert.strictEqual(startupCompleted, true,
+      'Async Meteor.startup() callback did not complete before tests ran. ' +
+      'See https://github.com/Meteor-Community-Packages/meteor-mocha/issues/176');
+  });
+});