diff --git a/testing/profiles/mochitest/user.js b/testing/profiles/mochitest/user.js
index 08784398f8a4..d2d542bb4af0 100644
--- a/testing/profiles/mochitest/user.js
+++ b/testing/profiles/mochitest/user.js
@@ -6,6 +6,9 @@
 // or if the profile folder is re-used after an exit(0) fast shutdown.
 user_pref("browser.sessionstore.resume_from_crash", false);
 
+// Better stacks for errors.
+user_pref("javascript.options.asyncstack_capture_debuggee_only", false);
+
 // Don't enable paint suppression when the background is unknown. While paint
 // is suppressed, synthetic click events and co. go to the old page, which can
 // be confusing for tests that send click events before the first paint.