diff --git a/xpcom/base/SlowAsynchronousTaskScheduler.cpp b/xpcom/base/SlowAsynchronousTaskScheduler.cpp
index f330fc526c..ff6c06d095 100644
--- a/xpcom/base/SlowAsynchronousTaskScheduler.cpp
+++ b/xpcom/base/SlowAsynchronousTaskScheduler.cpp
@@ -290,7 +290,7 @@ SlowAsynchronousTaskScheduler::IsScheduled(DependentSlowTask* aTasks,
   return false;
 }
 
-class SATSTimerTick : public CancelableRunnable
+class SATSTimerTick : public nsCancelableRunnable
 {
 public:
   NS_IMETHOD Run()