--- a/dom/media/webaudio/AudioEventTimeline.h
+++ b/dom/media/webaudio/AudioEventTimeline.h
@@ -149,16 +149,20 @@ public:
       return false;
     }
 
     if (aEvent.mType == AudioTimelineEvent::SetValueCurve) {
       if (!aEvent.mCurve || !aEvent.mCurveLength) {
         aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
         return false;
       }
+      if (aEvent.mDuration <= 0) {
+        aRv.Throw(NS_ERROR_RANGE_ERR);
+        return false;
+      }
     }
 
     bool timeAndValueValid = IsValid(aEvent.mValue) &&
                              IsValid(aEvent.mDuration);
     if (!timeAndValueValid) {
       aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
       return false;
     }