diff --git a/build/conformance.textproto b/build/conformance.textproto
index 43b498ef6c..7f8be026be 100644
--- a/build/conformance.textproto
+++ b/build/conformance.textproto
@@ -258,7 +258,6 @@ requirement: {
   whitelist_regexp: "demo/"
   whitelist_regexp: "test/"
   whitelist_regexp: "lib/util/delayed_tick.js"
-  whitelist_regexp: "lib/polyfill/abort_controller.js"
 }
 requirement: {
   type: BANNED_NAME