diff --git a/dom/messagechannel/MessagePortChild.cpp b/dom/messagechannel/MessagePortChild.cpp
index 98259e110758..4560b3c4d934 100644
--- a/dom/messagechannel/MessagePortChild.cpp
+++ b/dom/messagechannel/MessagePortChild.cpp
@@ -23,16 +23,18 @@ MessagePortChild::RecvStopSendingDataConfirmed()
 bool
 MessagePortChild::RecvEntangled(nsTArray<MessagePortMessage>&& aMessages)
 {
-  MOZ_ASSERT(mPort);
-  mPort->Entangled(aMessages);
+  if (mPort) {
+    mPort->Entangled(aMessages);
+  }
   return true;
 }
 
 bool
 MessagePortChild::RecvReceiveData(nsTArray<MessagePortMessage>&& aMessages)
 {
-  MOZ_ASSERT(mPort);
-  mPort->MessagesReceived(aMessages);
+  if (mPort) {
+    mPort->MessagesReceived(aMessages);
+  }
   return true;
 }