diff --git a/includes/upload/UploadBase.php b/includes/upload/UploadBase.php
index 08cc0171663..d9b5e23cb89 100644
--- a/includes/upload/UploadBase.php
+++ b/includes/upload/UploadBase.php
@@ -86,6 +86,7 @@ abstract class UploadBase {
 
 	protected static $safeXmlEncodings = [
 		'UTF-8',
+		'US-ASCII',
 		'ISO-8859-1',
 		'ISO-8859-2',
 		'UTF-16',
diff --git a/tests/phpunit/includes/upload/UploadBaseTest.php b/tests/phpunit/includes/upload/UploadBaseTest.php
index 2cbd1db5934..8e431019937 100644
--- a/tests/phpunit/includes/upload/UploadBaseTest.php
+++ b/tests/phpunit/includes/upload/UploadBaseTest.php
@@ -582,6 +582,7 @@ class UploadBaseTest extends MediaWikiIntegrationTestCase {
 			[ '<?xml version="1.0" encoding="utf-7"?><svg></svg>', true ],
 			[ '<?xml version="1.0" encoding="utf-8"?><svg></svg>', false ],
 			[ '<?xml version="1.0" encoding="WINDOWS-1252"?><svg></svg>', false ],
+			[ '<?xml version="1.0" encoding="us-ascii"?><svg></svg>', false ],
 		];
 	}