--- a/toolkit/components/url-classifier/tests/mochitest/test_classify_ping.html
+++ b/toolkit/components/url-classifier/tests/mochitest/test_classify_ping.html
@@ -47,19 +47,18 @@
     SpecialPowers.setBoolPref(TP_ENABLE_PREF, false);
 
     var msg = "ping should reach page in blacklist when tracking protection is off";
     var expectPing = true;
     var id = "2222";
     ping(id, host_track);
 
     return new Promise(function(resolve, reject) {
-      setTimeout(function() {
-        isPinged(id, expectPing, msg, resolve);
-      }, timeout);
+      // Retry at most 30 seconds.
+      isPingedWithRetry(id, expectPing, msg, resolve, 30 * 1000 / RETRY_TIMEOUT_MS);
     });
   }
 
   function testPingBlacklistSafebrowsingOn() {
     SpecialPowers.setBoolPref(TP_ENABLE_PREF, true);
 
     var msg = "ping should not reach page in blacklist when tracking protection is on";
     var expectPing = false;