diff --git a/.travis.yml b/.travis.yml
index 40539c9ab7..4512e5eb1b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -111,7 +111,9 @@ script:
       npm run test:php -- --verbose -c tests/phpunit/multisite.xml &&
       npm run test:php -- --verbose -c tests/phpunit/multisite.xml --group ms-files &&
       npm run test:php -- --verbose -c phpunit.xml.dist --group external-http &&
-      npm run test:php -- --verbose -c phpunit.xml.dist --group restapi-jsclient
+      npm run test:php -- --verbose -c phpunit.xml.dist --group restapi-jsclient &&
+      # __fakegroup__ is excluded to force PHPUnit to ignore the <exclude> settings in phpunit.xml.dist.
+      LOCAL_PHP_XDEBUG=true npm run test:php -- -v --group xdebug --exclude-group __fakegroup__
     elif [[ "$WP_TRAVISCI" == "lint:php" ]]; then
       docker-compose run --rm php composer format &&
       docker-compose run --rm php composer lint:errors &&
diff --git a/tests/phpunit/tests/ajax/Response.php b/tests/phpunit/tests/ajax/Response.php
index 1ee2eb39ea..83def22b8f 100644
--- a/tests/phpunit/tests/ajax/Response.php
+++ b/tests/phpunit/tests/ajax/Response.php
@@ -69,6 +69,7 @@ class Tests_Ajax_Response extends WP_UnitTestCase {
 	 * @ticket 19448
 	 * @runInSeparateProcess
 	 * @preserveGlobalState disabled
+	 * @group xdebug
 	 */
 	public function test_response_charset_in_header() {
 
diff --git a/tests/phpunit/tests/oembed/headers.php b/tests/phpunit/tests/oembed/headers.php
index 6fc4ae6800..adc3ff93c2 100644
--- a/tests/phpunit/tests/oembed/headers.php
+++ b/tests/phpunit/tests/oembed/headers.php
@@ -5,6 +5,7 @@
  * @preserveGlobalState disabled
  * @group oembed
  * @group oembed-headers
+ * @group xdebug
  */
 class Tests_oEmbed_HTTP_Headers extends WP_UnitTestCase {
 	function test_rest_pre_serve_request_headers() {