diff --git a/dom/workers/WorkerPrefs.h b/dom/workers/WorkerPrefs.h
index 31a00e4290..a8a1e61f4f 100644
--- a/dom/workers/WorkerPrefs.h
+++ b/dom/workers/WorkerPrefs.h
@@ -26,7 +26,7 @@ WORKER_SIMPLE_PREF("browser.dom.window.dump.enabled", DumpEnabled, DUMP)
 WORKER_SIMPLE_PREF("canvas.imagebitmap_extensions.enabled", ImageBitmapExtensionsEnabled, IMAGEBITMAP_EXTENSIONS_ENABLED)
 WORKER_SIMPLE_PREF("dom.caches.enabled", DOMCachesEnabled, DOM_CACHES)
 WORKER_SIMPLE_PREF("dom.caches.testing.enabled", DOMCachesTestingEnabled, DOM_CACHES_TESTING)
-WORKER_SIMPLE_PREF("dom.min_timeout_value", DOMMinTimoutValue, DOM_MIN_TIMEOUT_VALUE)
+WORKER_SIMPLE_PREF("dom.min_timeout_value", DOMMinTimeoutValue, DOM_MIN_TIMEOUT_VALUE)
 WORKER_SIMPLE_PREF("dom.performance.enable_user_timing_logging", PerformanceLoggingEnabled, PERFORMANCE_LOGGING_ENABLED)
 WORKER_SIMPLE_PREF("dom.webnotifications.enabled", DOMWorkerNotificationEnabled, DOM_WORKERNOTIFICATION)
 WORKER_SIMPLE_PREF("dom.webnotifications.serviceworker.enabled", DOMServiceWorkerNotificationEnabled, DOM_SERVICEWORKERNOTIFICATION)
diff --git a/dom/workers/WorkerPrivate.cpp b/dom/workers/WorkerPrivate.cpp
index 35d8dd744b..9c52c789cc 100644
--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -1999,18 +1999,13 @@ struct WorkerPrivate::TimeoutInfo
     auto target = mInterval;
     int32_t minTimeoutValue;
     
-    if (NS_IsMainThread()) {
-      // We can get the pref value directly.
-      minTimeoutValue = Preferences::GetInt("dom.min_timeout_value");
+    // We're on a worker thread; go through WorkerPrivate for the pref.
+    WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(aCx);
+    if (workerPrivate) {
+      minTimeoutValue = workerPrivate->DOMMinTimeoutValue();
     } else {
-      // We're on a worker thread; go through WorkerPrivate.
-      WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(aCx);
-      if (workerPrivate) {
-        minTimeoutValue = workerPrivate->DOMMinTimoutValue();
-      } else {
-        // fall back to default 4 ms
-        minTimeoutValue = 4;
-      }
+      // fall back to default 4 ms
+      minTimeoutValue = 4;
     }
       
     // Clamp timeout for workers, except chrome workers