diff --git a/docs/api/assert/pushResult.md b/docs/api/assert/pushResult.md
index d34eeddaa..8d058c0e0 100644
--- a/docs/api/assert/pushResult.md
+++ b/docs/api/assert/pushResult.md
@@ -18,8 +18,8 @@ Report the result of a custom assertion.
 | name | description |
 |------|-------------|
 | `data.result` (boolean) | Result of the assertion |
-| `data.actual` | Expression being tested |
-| `data.expected` | Known comparison value |
+| `data.actual` | Expression being tested (optional) |
+| `data.expected` | Known comparison value (optional) |
 | `data.message` (string or undefined) | Short description of the assertion |
 
 ## Examples
diff --git a/docs/resources/example-fail.html b/docs/resources/example-fail.html
index 53989f407..6717da03d 100644
--- a/docs/resources/example-fail.html
+++ b/docs/resources/example-fail.html
@@ -14,7 +14,7 @@
   });
   QUnit.test('banana', function (assert) {
     assert.true(true, 'foo');
-    var sentence = 'This is actual.';
+    const sentence = 'This is actual.';
     assert.equal(sentence, 'This is expected.', 'example sentence');
     assert.true(true, 'bar');
     assert.true(true, 'baz');
diff --git a/src/core/on-uncaught-exception.js b/src/core/on-uncaught-exception.js
index 21f6744f2..a0e8f1899 100644
--- a/src/core/on-uncaught-exception.js
+++ b/src/core/on-uncaught-exception.js
@@ -25,6 +25,7 @@ import { emit } from './events.js';
  */
 export default function onUncaughtException (error) {
   if (config.current) {
+    // This omits 'actual' and 'expected' (undefined)
     config.current.assert.pushResult({
       result: false,
       message: `global failure: ${errorString(error)}`,
diff --git a/src/core/reporters/HtmlReporter.js b/src/core/reporters/HtmlReporter.js
index 80157faca..54594dba7 100644
--- a/src/core/reporters/HtmlReporter.js
+++ b/src/core/reporters/HtmlReporter.js
@@ -842,11 +842,12 @@ export default class HtmlReporter {
     let actual;
 
     // When pushFailure() is called, it is implied that no expected value
-    // or diff should be shown. It does not set details.expected.
+    // or diff should be shown, because both expected and actual as undefined.
     //
     // This must check details.expected existence. If it exists as undefined,
     // that's a regular assertion for which to render actual/expected and a diff.
-    if (!details.result && hasOwn.call(details, 'expected')) {
+    const showAnyValues = !details.result && (details.expected !== undefined || details.actual !== undefined);
+    if (showAnyValues) {
       if (details.negative) {
         expected = 'NOT ' + dump.parse(details.expected);
       } else {
diff --git a/src/core/reporters/TapReporter.js b/src/core/reporters/TapReporter.js
index a4fed0f69..b102af584 100644
--- a/src/core/reporters/TapReporter.js
+++ b/src/core/reporters/TapReporter.js
@@ -3,8 +3,6 @@ import { errorString } from '../utilities.js';
 import { console } from '../globals.js';
 import { annotateStacktrace } from '../stacktrace.js';
 
-const hasOwn = Object.prototype.hasOwnProperty;
-
 /**
  * Format a given value into YAML.
  *
@@ -259,11 +257,12 @@ export default class TapReporter {
     out += `\n  message: ${prettyYamlValue(error.message || 'failed')}`;
     out += `\n  severity: ${prettyYamlValue(severity || 'failed')}`;
 
-    if (hasOwn.call(error, 'actual')) {
+    // When pushFailure() is used, actual/expected are initially unset but
+    // eventually in Test#logAssertion, for testReport#pushAssertion, these are
+    // forged into existence as undefined.
+    const hasAny = (error.expected !== undefined || error.actual !== undefined);
+    if (hasAny) {
       out += `\n  actual  : ${prettyYamlValue(error.actual)}`;
-    }
-
-    if (hasOwn.call(error, 'expected')) {
       out += `\n  expected: ${prettyYamlValue(error.expected)}`;
     }
 
diff --git a/src/core/test.js b/src/core/test.js
index 049682282..58de323ca 100644
--- a/src/core/test.js
+++ b/src/core/test.js
@@ -572,7 +572,6 @@ Test.prototype = {
     this.pushResult({
       result: false,
       message: message || 'error',
-      actual: null,
       source
     });
   },
diff --git a/test/cli/cli-main.js b/test/cli/cli-main.js
index f0c2ad59c..8b5e538b7 100644
--- a/test/cli/cli-main.js
+++ b/test/cli/cli-main.js
@@ -39,8 +39,6 @@ not ok 2 slow
   ---
   message: Test took longer than 7ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/assert-expect-failure-step.tap.txt b/test/cli/fixtures/assert-expect-failure-step.tap.txt
index a25b2f93b..5c316f328 100644
--- a/test/cli/fixtures/assert-expect-failure-step.tap.txt
+++ b/test/cli/fixtures/assert-expect-failure-step.tap.txt
@@ -7,8 +7,6 @@ not ok 3 wrong [a little off]
   ---
   message: Expected 2 assertions, but 1 were run
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-failure-step.js:22:7
         at internal
@@ -17,8 +15,6 @@ not ok 4 wrong [way off]
   ---
   message: Expected 5 assertions, but 1 were run
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-failure-step.js:30:7
         at internal
@@ -29,8 +25,6 @@ not ok 5 previously passing [once]
     Expected 4 assertions, but 2 were run.
     It looks like you are upgrading from QUnit 2. Steps no longer count as separate assertions. https://qunitjs.com/api/assert/expect/
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-failure-step.js:40:7
         at internal
@@ -41,8 +35,6 @@ not ok 6 previously passing [twice]
     Expected 9 assertions, but 4 were run.
     It looks like you are upgrading from QUnit 2. Steps no longer count as separate assertions. https://qunitjs.com/api/assert/expect/
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-failure-step.js:49:7
         at internal
diff --git a/test/cli/fixtures/assert-expect-failure.tap.txt b/test/cli/fixtures/assert-expect-failure.tap.txt
index ca7938917..9a0fed475 100644
--- a/test/cli/fixtures/assert-expect-failure.tap.txt
+++ b/test/cli/fixtures/assert-expect-failure.tap.txt
@@ -6,8 +6,6 @@ not ok 1 failing test
   ---
   message: Expected 2 assertions, but 1 were run
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-failure.js:1:7
         at internal
diff --git a/test/cli/fixtures/assert-expect-no-assertions.tap.txt b/test/cli/fixtures/assert-expect-no-assertions.tap.txt
index a30494830..12519e7b6 100644
--- a/test/cli/fixtures/assert-expect-no-assertions.tap.txt
+++ b/test/cli/fixtures/assert-expect-no-assertions.tap.txt
@@ -6,8 +6,6 @@ not ok 1 no assertions
   ---
   message: Expected at least one assertion, but none were run - call expect(0) to accept zero assertions.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/assert-expect-no-assertions.js:1:7
         at internal
diff --git a/test/cli/fixtures/async-test-throw.tap.txt b/test/cli/fixtures/async-test-throw.tap.txt
index 4bad22156..3a41184d1 100644
--- a/test/cli/fixtures/async-test-throw.tap.txt
+++ b/test/cli/fixtures/async-test-throw.tap.txt
@@ -5,8 +5,6 @@ not ok 1 throw early
   ---
   message: "Promise rejected during \"throw early\": boo"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: boo
         at /qunit/test/cli/fixtures/async-test-throw.js:2:9
@@ -15,8 +13,6 @@ not ok 2 throw late
   ---
   message: "Promise rejected during \"throw late\": boo"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: boo
         at /qunit/test/cli/fixtures/async-test-throw.js:8:9
@@ -25,8 +21,6 @@ not ok 3 test with bad thenable
   ---
   message: "Promise rejected during \"test with bad thenable\": boo"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: boo
         at /qunit/test/cli/fixtures/async-test-throw.js:16:13
diff --git a/test/cli/fixtures/config-noglobals-add.tap.txt b/test/cli/fixtures/config-noglobals-add.tap.txt
index 5f502247a..51f74e85e 100644
--- a/test/cli/fixtures/config-noglobals-add.tap.txt
+++ b/test/cli/fixtures/config-noglobals-add.tap.txt
@@ -6,8 +6,6 @@ not ok 1 adds global var
   ---
   message: Introduced global variable(s): dummyGlobal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at qunit.js
   ...
diff --git a/test/cli/fixtures/config-noglobals-remove.tap.txt b/test/cli/fixtures/config-noglobals-remove.tap.txt
index e02489100..57d853388 100644
--- a/test/cli/fixtures/config-noglobals-remove.tap.txt
+++ b/test/cli/fixtures/config-noglobals-remove.tap.txt
@@ -6,8 +6,6 @@ not ok 1 deletes global var
   ---
   message: Deleted global variable(s): dummyGlobal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at qunit.js
   ...
@@ -17,4 +15,4 @@ not ok 1 deletes global var
 # todo 0
 # fail 1
 
-# exit code: 1
\ No newline at end of file
+# exit code: 1
diff --git a/test/cli/fixtures/config-notrycatch-hook-rejection.tap.txt b/test/cli/fixtures/config-notrycatch-hook-rejection.tap.txt
index a5c0121ac..289194d47 100644
--- a/test/cli/fixtures/config-notrycatch-hook-rejection.tap.txt
+++ b/test/cli/fixtures/config-notrycatch-hook-rejection.tap.txt
@@ -6,16 +6,12 @@ not ok 1 example > passing test
   ---
   message: global failure: bad things happen
   severity: failed
-  actual  : undefined
-  expected: undefined
   stack: |
         at internal
   ...
   ---
   message: Test took longer than 1000ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/config-notrycatch-test-rejection.tap.txt b/test/cli/fixtures/config-notrycatch-test-rejection.tap.txt
index 48d5817d1..30d661445 100644
--- a/test/cli/fixtures/config-notrycatch-test-rejection.tap.txt
+++ b/test/cli/fixtures/config-notrycatch-test-rejection.tap.txt
@@ -6,16 +6,12 @@ not ok 1 example > returns a rejected promise
   ---
   message: global failure: bad things happen
   severity: failed
-  actual  : undefined
-  expected: undefined
   stack: |
         at internal
   ...
   ---
   message: Test took longer than 1000ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/config-requireExpects.tap.txt b/test/cli/fixtures/config-requireExpects.tap.txt
index 964327a06..99774f615 100644
--- a/test/cli/fixtures/config-requireExpects.tap.txt
+++ b/test/cli/fixtures/config-requireExpects.tap.txt
@@ -6,8 +6,6 @@ not ok 1 passing test
   ---
   message: Expected number of assertions to be defined, but expect() was not called.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at /qunit/test/cli/fixtures/config-requireExpects.js:3:7
         at internal
@@ -18,4 +16,4 @@ not ok 1 passing test
 # todo 0
 # fail 1
 
-# exit code: 1
\ No newline at end of file
+# exit code: 1
diff --git a/test/cli/fixtures/config-testTimeout.tap.txt b/test/cli/fixtures/config-testTimeout.tap.txt
index cb4da3807..5a1f25372 100644
--- a/test/cli/fixtures/config-testTimeout.tap.txt
+++ b/test/cli/fixtures/config-testTimeout.tap.txt
@@ -6,8 +6,6 @@ not ok 1 slow
   ---
   message: Test took longer than 10ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/done-after-timeout.tap.txt b/test/cli/fixtures/done-after-timeout.tap.txt
index f0afcbc26..54e72b97d 100644
--- a/test/cli/fixtures/done-after-timeout.tap.txt
+++ b/test/cli/fixtures/done-after-timeout.tap.txt
@@ -6,8 +6,6 @@ not ok 1 times out before scheduled done is called
   ---
   message: Test took longer than 10ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
@@ -17,4 +15,4 @@ not ok 1 times out before scheduled done is called
 # todo 0
 # fail 1
 
-# exit code: 1
\ No newline at end of file
+# exit code: 1
diff --git a/test/cli/fixtures/drooling-done.tap.txt b/test/cli/fixtures/drooling-done.tap.txt
index 082583c9e..c558cfdf5 100644
--- a/test/cli/fixtures/drooling-done.tap.txt
+++ b/test/cli/fixtures/drooling-done.tap.txt
@@ -9,8 +9,6 @@ not ok 1 Test A
         at /qunit/test/cli/fixtures/drooling-done.js:5:7
         at internal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: this is an intentional error
         at /qunit/test/cli/fixtures/drooling-done.js:8:9
diff --git a/test/cli/fixtures/drooling-extra-done.tap.txt b/test/cli/fixtures/drooling-extra-done.tap.txt
index 154359cb5..0eeaa41ed 100644
--- a/test/cli/fixtures/drooling-extra-done.tap.txt
+++ b/test/cli/fixtures/drooling-extra-done.tap.txt
@@ -11,8 +11,6 @@ not ok 2 Test B
         at /qunit/test/cli/fixtures/drooling-extra-done.js:13:7
         at internal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: Unexpected release of async pause during a different test.
     > Test: Test A [async #1]
diff --git a/test/cli/fixtures/hanging-test.tap.txt b/test/cli/fixtures/hanging-test.tap.txt
index 11db9e465..347016660 100644
--- a/test/cli/fixtures/hanging-test.tap.txt
+++ b/test/cli/fixtures/hanging-test.tap.txt
@@ -1,13 +1,11 @@
 # name: test that hangs
-# command: ["qunit","hanging-test.js"]
+# command: ["qunit", "hanging-test.js"]
 
 TAP version 13
 not ok 1 hanging
   ---
   message: Test took longer than 3000ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/hooks-global-throw.tap.txt b/test/cli/fixtures/hooks-global-throw.tap.txt
index 8b8d8b8a1..1a234c1fe 100644
--- a/test/cli/fixtures/hooks-global-throw.tap.txt
+++ b/test/cli/fixtures/hooks-global-throw.tap.txt
@@ -5,8 +5,6 @@ not ok 1 global hook throws
   ---
   message: Global beforeEach failed on global hook throws: Error: banana
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: banana
         at /qunit/test/cli/fixtures/hooks-global-throw.js:3:11
@@ -14,8 +12,6 @@ not ok 1 global hook throws
   ---
   message: Global afterEach failed on global hook throws: Error: apple
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: apple
         at /qunit/test/cli/fixtures/hooks-global-throw.js:17:11
@@ -24,8 +20,6 @@ not ok 2 global hook rejects
   ---
   message: "Promise rejected before \"global hook rejects\": banana"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: banana
         at /qunit/test/cli/fixtures/hooks-global-throw.js:5:27
@@ -33,8 +27,6 @@ not ok 2 global hook rejects
   ---
   message: "Promise rejected after \"global hook rejects\": apple"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: apple
         at /qunit/test/cli/fixtures/hooks-global-throw.js:19:27
@@ -43,8 +35,6 @@ not ok 3 global hook with bad thenable
   ---
   message: "Promise rejected before \"global hook with bad thenable\": global brocoli"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: global brocoli
         at /qunit/test/cli/fixtures/hooks-global-throw.js:9:15
@@ -52,8 +42,6 @@ not ok 3 global hook with bad thenable
   ---
   message: "Promise rejected after \"global hook with bad thenable\": global artichoke"
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: global artichoke
         at /qunit/test/cli/fixtures/hooks-global-throw.js:23:15
diff --git a/test/cli/fixtures/pending-async-after-timeout.tap.txt b/test/cli/fixtures/pending-async-after-timeout.tap.txt
index 127374998..a8641fa57 100644
--- a/test/cli/fixtures/pending-async-after-timeout.tap.txt
+++ b/test/cli/fixtures/pending-async-after-timeout.tap.txt
@@ -1,13 +1,11 @@
 # name: test with pending async after timeout
-# command: ["qunit","pending-async-after-timeout.js"]
+# command: ["qunit", "pending-async-after-timeout.js"]
 
 TAP version 13
 not ok 1 example
   ---
   message: Test took longer than 10ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
@@ -17,4 +15,4 @@ not ok 1 example
 # todo 0
 # fail 1
 
-# exit code: 1
\ No newline at end of file
+# exit code: 1
diff --git a/test/cli/fixtures/timeout.tap.txt b/test/cli/fixtures/timeout.tap.txt
index 5b66bd991..b29da673f 100644
--- a/test/cli/fixtures/timeout.tap.txt
+++ b/test/cli/fixtures/timeout.tap.txt
@@ -6,8 +6,6 @@ not ok 1 timeout > first
   ---
   message: Test took longer than 10ms; test timed out.
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
         at internal
   ...
diff --git a/test/cli/fixtures/too-many-done-calls.tap.txt b/test/cli/fixtures/too-many-done-calls.tap.txt
index a2c18b528..5610acded 100644
--- a/test/cli/fixtures/too-many-done-calls.tap.txt
+++ b/test/cli/fixtures/too-many-done-calls.tap.txt
@@ -10,8 +10,6 @@ not ok 1 Test A
         at /qunit/test/cli/fixtures/too-many-done-calls.js:1:7
         at internal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: Tried to release async pause that was already released.
     > Test: Test A [async #1]
diff --git a/test/cli/fixtures/uncaught-error-after-assert-async.tap.txt b/test/cli/fixtures/uncaught-error-after-assert-async.tap.txt
index 9d6533222..c7c1e4d89 100644
--- a/test/cli/fixtures/uncaught-error-after-assert-async.tap.txt
+++ b/test/cli/fixtures/uncaught-error-after-assert-async.tap.txt
@@ -9,8 +9,6 @@ not ok 1 contains a hard error after using assert.async()
         at /qunit/test/cli/fixtures/uncaught-error-after-assert-async.js:1:7
         at internal
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: expected error thrown in test
         at /qunit/test/cli/fixtures/uncaught-error-after-assert-async.js:4:9
diff --git a/test/cli/fixtures/uncaught-error-in-hook.tap.txt b/test/cli/fixtures/uncaught-error-in-hook.tap.txt
index 3126b2169..52d776e4e 100644
--- a/test/cli/fixtures/uncaught-error-in-hook.tap.txt
+++ b/test/cli/fixtures/uncaught-error-in-hook.tap.txt
@@ -6,8 +6,6 @@ not ok 1 contains a hard error in hook > contains a hard error
   ---
   message: before failed on contains a hard error: expected error thrown in hook
   severity: failed
-  actual  : null
-  expected: undefined
   stack: |
     Error: expected error thrown in hook
         at /qunit/test/cli/fixtures/uncaught-error-in-hook.js:3:11
diff --git a/test/cli/fixtures/unhandled-rejection.tap.txt b/test/cli/fixtures/unhandled-rejection.tap.txt
index 4d331724b..0262181ee 100644
--- a/test/cli/fixtures/unhandled-rejection.tap.txt
+++ b/test/cli/fixtures/unhandled-rejection.tap.txt
@@ -18,8 +18,6 @@ not ok 2 Unhandled Rejections > test passes just fine, but has a rejected promis
   ---
   message: global failure: Error: Error thrown in non-returned promise!
   severity: failed
-  actual  : undefined
-  expected: undefined
   stack: |
     Error: Error thrown in non-returned promise!
         at /qunit/test/cli/fixtures/unhandled-rejection.js:10:13