diff --git a/tests/phpunit/tests/functions/wpAuthCheck.php b/tests/phpunit/tests/functions/wpAuthCheck.php
new file mode 100644
index 0000000000..85e26fb867
--- /dev/null
+++ b/tests/phpunit/tests/functions/wpAuthCheck.php
@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * @group functions.php
+ *
+ * Tests for the behavior of `wp_auth_check()`
+ */
+class Tests_Functions_WP_Auth_Check extends WP_UnitTestCase {
+
+	/**
+	 * Run with user not logged in.
+	 *
+	 * @ticket 41860
+	 */
+	function test_wp_auth_check_user_not_logged_in() {
+		$expected = array(
+			'wp-auth-check' => false,
+		);
+
+		$this->assertFalse( is_user_logged_in() );
+		$this->assertSame( $expected, wp_auth_check( array() ) );
+	}
+
+	/**
+	 * Run with user logged in.
+	 *
+	 * @ticket 41860
+	 */
+	function test_wp_auth_check_user_logged_in() {
+		// log user in
+		wp_set_current_user( 1 );
+
+		$expected = array(
+			'wp-auth-check' => true,
+		);
+
+		$this->assertTrue( is_user_logged_in() );
+		$this->assertSame( $expected, wp_auth_check( array() ) );
+	}
+
+	/**
+	 * Run with user logged in but with expired state.
+	 *
+	 * @ticket 41860
+	 */
+	function test_wp_auth_check_user_logged_in_login_grace_period_set() {
+		// log user in
+		wp_set_current_user( 1 );
+
+		$GLOBALS['login_grace_period'] = 1;
+
+		$expected = array(
+			'wp-auth-check' => false,
+		);
+		$actual = wp_auth_check( array() );
+		$logged_in = is_user_logged_in();
+
+		// Leave the global state unchanged
+		unset( $GLOBALS['login_grace_period'] );
+
+		$this->assertTrue( $logged_in );
+		$this->assertSame( $expected, $actual );
+	}
+}