diff --git a/test/unit/ajax.js b/test/unit/ajax.js
index fe831d0b1..db0af6cec 100644
--- a/test/unit/ajax.js
+++ b/test/unit/ajax.js
@@ -2280,7 +2280,10 @@ if ( typeof window.ArrayBuffer === "undefined" || typeof new XMLHttpRequest().re
 	// Chrome 78 dropped support for synchronous XHR requests inside of
 	// beforeunload, unload, pagehide, and visibilitychange event handlers.
 	// See https://bugs.chromium.org/p/chromium/issues/detail?id=952452
-	if ( !/chrome/i.test( navigator.userAgent ) ) {
+	// Safari 13 did similar changes. The below check will catch them both.
+	// Edge Legacy fakes Chrome which fakes Safari in their user agents so we need
+	// to exclude Edge specifically here so that the test continues to run there.
+	if ( !/safari/i.test( navigator.userAgent ) || /edge\//i.test( navigator.userAgent ) ) {
 		testIframe(
 			"#14379 - jQuery.ajax() on unload",
 			"ajax/onunload.html",