diff --git a/src/wp-includes/kses.php b/src/wp-includes/kses.php
index b1b7c7319a..df07c6c10b 100644
--- a/src/wp-includes/kses.php
+++ b/src/wp-includes/kses.php
@@ -2423,6 +2423,7 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 			'direction',
 			'float',
 			'list-style-type',
+			'object-fit',
 			'object-position',
 			'overflow',
 			'vertical-align',
diff --git a/tests/phpunit/tests/kses.php b/tests/phpunit/tests/kses.php
index 8ea6f44ffc..294cb84779 100644
--- a/tests/phpunit/tests/kses.php
+++ b/tests/phpunit/tests/kses.php
@@ -1112,6 +1112,11 @@ EOF;
 				'css'      => 'object-position: right top',
 				'expected' => 'object-position: right top',
 			),
+			// `object-fit` introduced in 6.1.
+			array(
+				'css'      => 'object-fit: cover',
+				'expected' => 'object-fit: cover',
+			),
 			// Expressions are not allowed.
 			array(
 				'css'      => 'height: expression( body.scrollTop + 50 + "px" )',