diff --git a/uriloader/exthandler/tests/mochitest/browser.ini b/uriloader/exthandler/tests/mochitest/browser.ini
index 22bae61c787a..b1a3c51a2057 100644
--- a/uriloader/exthandler/tests/mochitest/browser.ini
+++ b/uriloader/exthandler/tests/mochitest/browser.ini
@@ -85,8 +85,10 @@ support-files =
   file_txt_attachment_test.txt
   file_txt_attachment_test.txt^headers^
 [browser_open_internal_choice_persistence.js]
-skip-if =
-  apple_silicon # bug 1752482
+skip-if = [
+   "apple_silicon", #bug 1752482
+   "os == 'mac' && os_version == '10.15'", #Bug 1776017
+]
 support-files =
   file_pdf_application_pdf.pdf
   file_pdf_application_pdf.pdf^headers^