--- a/dom/media/MediaInfo.h
+++ b/dom/media/MediaInfo.h
@@ -499,16 +499,20 @@ public:
       : mChannelMap(0)
       , mValid(false)
     {}
     explicit ChannelLayout(uint32_t aChannels)
       : ChannelLayout(aChannels, SMPTEDefault(aChannels))
     {}
     ChannelLayout(uint32_t aChannels, const Channel* aConfig)
     {
+      if (!aConfig) {
+        mValid = false;
+        return;
+      }
       mChannels.AppendElements(aConfig, aChannels);
       UpdateChannelMap();
     }
     bool operator==(const ChannelLayout& aOther) const
     {
       return mChannels == aOther.mChannels;
     }
     bool operator!=(const ChannelLayout& aOther) const