diff --git a/CHANGELOG.md b/CHANGELOG.md
index de4a49ed7..3bfb9301d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## v1.0.4 - 2024-04-17
+
+### Added
+
+- Define the `WP_RUN_CORE_TESTS` constant during unit tests.
+
+### Fixed
+
+- Ensure that dumping the content dumps non-json content,
+
 ## v1.0.3 - 2024-04-15
 
 ### Fixed
diff --git a/src/mantle/testing/wordpress-bootstrap.php b/src/mantle/testing/wordpress-bootstrap.php
index 75b1cceed..cd027b3cb 100644
--- a/src/mantle/testing/wordpress-bootstrap.php
+++ b/src/mantle/testing/wordpress-bootstrap.php
@@ -94,6 +94,11 @@
 define( 'WP_TESTS_TABLE_PREFIX', $table_prefix );
 define( 'DIR_TESTDATA', __DIR__ . '/data' );
 
+// Set the core test constant.
+if ( ! defined( 'WP_RUN_CORE_TESTS' ) ) {
+	define( 'WP_RUN_CORE_TESTS', true );
+}
+
 /*
  * Cron tries to make an HTTP request to the site, which always fails,
  * because tests are run in CLI mode only.