--- a/devtools/client/webconsole/new-console-output/test/fixtures/stub-generators/head.js
+++ b/devtools/client/webconsole/new-console-output/test/fixtures/stub-generators/head.js
@@ -408,22 +408,21 @@ function* generatePageErrorStubs() {
     packets: [],
   };
 
   let toolbox = yield openNewTabAndToolbox(TEST_URI, "webconsole");
 
   for (let [key, code] of pageError) {
     let received = new Promise(resolve => {
       toolbox.target.client.addListener("pageError", function onPacket(e, packet) {
+        toolbox.target.client.removeListener("pageError", onPacket);
         let message = prepareMessage(packet, {getNextId: () => 1});
         stubs.packets.push(formatPacket(message.messageText, packet));
         stubs.preparedMessages.push(formatStub(message.messageText, packet));
         resolve();
-      }, {
-        once: true
       });
     });
 
     yield ContentTask.spawn(
       gBrowser.selectedBrowser,
       [key, code],
       function ([subKey, subCode]) {
         let script = content.document.createElement("script");