diff --git a/Gruntfile.js b/Gruntfile.js
index 38f4db48f..5d59aaf3f 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -128,6 +128,7 @@ module.exports = function (grunt) {
         'test/main/diff.js',
         'test/main/dump.js',
         'test/main/each.js',
+        'test/main/events.js',
         'test/main/HtmlReporter.js',
         'test/main/modules.js',
         'test/main/modules-es2018.js',
diff --git a/src/events.js b/src/events.js
index fe02b3a24..81d6a2174 100644
--- a/src/events.js
+++ b/src/events.js
@@ -28,6 +28,7 @@ const MEMORY_EVENTS = [
  * @return {void}
  */
 export function emit (eventName, data) {
+  /* istanbul ignore if: private function */
   if (typeof eventName !== 'string') {
     throw new TypeError('eventName must be a string when emitting an event');
   }
diff --git a/test/index-es5.html b/test/index-es5.html
index b7ea181fc..b18da4dfc 100644
--- a/test/index-es5.html
+++ b/test/index-es5.html
@@ -20,6 +20,7 @@
   <script src="main/diff.js"></script>
   <script src="main/dump.js"></script>
   <script src="main/each.js"></script>
+  <script src="main/events.js"></script>
   <script src="main/HtmlReporter.js"></script>
   <script src="main/legacy.js"></script>
   <script src="main/modules.js"></script>
diff --git a/test/index-xhtml.xhtml b/test/index-xhtml.xhtml
index e566f1db2..c441262be 100644
--- a/test/index-xhtml.xhtml
+++ b/test/index-xhtml.xhtml
@@ -32,6 +32,7 @@
   <script src="main/diff.js"></script>
   <script src="main/dump.js"></script>
   <script src="main/each.js"></script>
+  <script src="main/events.js"></script>
   <script src="main/HtmlReporter.js"></script>
   <script src="main/legacy.js"></script>
   <script src="main/modules-es2018.js"></script>
diff --git a/test/index.html b/test/index.html
index c0807c405..62c9ca523 100644
--- a/test/index.html
+++ b/test/index.html
@@ -20,6 +20,7 @@
   <script src="main/diff.js"></script>
   <script src="main/dump.js"></script>
   <script src="main/each.js"></script>
+  <script src="main/events.js"></script>
   <script src="main/HtmlReporter.js"></script>
   <script src="main/legacy.js"></script>
   <script src="main/modules-es2018.js"></script>
diff --git a/test/main/assert-step.js b/test/main/assert-step.js
index 3972aed7f..383b29708 100644
--- a/test/main/assert-step.js
+++ b/test/main/assert-step.js
@@ -116,6 +116,10 @@ QUnit.module('assert.step', function () {
     assert.verifySteps(['two']);
   });
 
+  QUnit.test('empty verifySteps()', function (assert) {
+    assert.verifySteps([]);
+  });
+
   QUnit.test('errors if not called when `assert.step` is used', function (assert) {
     assert.expect(2);
     assert.step('one');
diff --git a/test/main/events.js b/test/main/events.js
new file mode 100644
index 000000000..e01a26764
--- /dev/null
+++ b/test/main/events.js
@@ -0,0 +1,25 @@
+QUnit.module('events', function () {
+  QUnit.test('QUnit.on [failure]', function (assert) {
+    assert.throws(function () {
+      QUnit.on(null, function () {
+        assert.step('null called');
+      });
+    }, /must be a string/, 'null event name');
+
+    assert.throws(function () {
+      QUnit.on('banana', function () {
+        assert.step('banana called');
+      });
+    }, /not a valid event/, 'unknown event name');
+
+    assert.throws(function () {
+      QUnit.on('runStart');
+    }, /must be a function/, 'missing callback');
+
+    assert.throws(function () {
+      QUnit.on('runStart', null);
+    }, /must be a function/, 'null callback');
+
+    assert.verifySteps([]);
+  });
+});
diff --git a/test/mozjs.js b/test/mozjs.js
index 4c9f83a4f..3ef2db4b4 100644
--- a/test/mozjs.js
+++ b/test/mozjs.js
@@ -22,6 +22,7 @@ loadRelativeToScript('../test/main/deepEqual.js');
 loadRelativeToScript('../test/main/diff.js');
 loadRelativeToScript('../test/main/dump.js');
 loadRelativeToScript('../test/main/each.js');
+loadRelativeToScript('../test/main/events.js');
 loadRelativeToScript('../test/main/HtmlReporter.js');
 // loadRelativeToScript( "../test/main/modules.js" ); // Requires setTimeout
 loadRelativeToScript('../test/main/modules-es2018.js');
diff --git a/test/mozjs.mjs b/test/mozjs.mjs
index 58d540178..0e0440a3a 100644
--- a/test/mozjs.mjs
+++ b/test/mozjs.mjs
@@ -11,6 +11,7 @@ import '../test/main/deepEqual.js';
 import '../test/main/diff.js';
 import '../test/main/dump.js';
 import '../test/main/each.js';
+import '../test/main/events.js';
 import '../test/main/HtmlReporter.js';
 // import  "../test/main/modules.js"; // Requires setTimeout
 import '../test/main/modules-es2018.js';
diff --git a/test/webWorker-worker.js b/test/webWorker-worker.js
index 69e92a5da..1f8954fbe 100644
--- a/test/webWorker-worker.js
+++ b/test/webWorker-worker.js
@@ -16,6 +16,7 @@ importScripts(
   'main/diff.js',
   'main/dump.js',
   'main/each.js',
+  'main/events.js',
   'main/HtmlReporter.js',
   'main/modules.js',
   'main/modules-es2018.js',