diff --git a/toolkit/components/extensions/test/mochitest/mochitest-common.ini b/toolkit/components/extensions/test/mochitest/mochitest-common.ini
index bc029748f042..90c93f52171d 100644
--- a/toolkit/components/extensions/test/mochitest/mochitest-common.ini
+++ b/toolkit/components/extensions/test/mochitest/mochitest-common.ini
@@ -112,6 +112,7 @@ skip-if = (toolkit == 'android') # bug 1342577
 [test_ext_redirect_jar.html]
 skip-if = os == 'win' && (debug || asan) # Bug 1563440
 [test_ext_request_urlClassification.html]
+skip-if = fission # Bug 1579335
 [test_ext_runtime_connect.html]
 [test_ext_runtime_connect_twoway.html]
 [test_ext_runtime_connect2.html]