--- a/dom/media/webrtc/MediaEngineWebRTC.cpp
+++ b/dom/media/webrtc/MediaEngineWebRTC.cpp
@@ -73,16 +73,17 @@ void AudioInputCubeb::UpdateDeviceList()
   // stashed indexes.
   // For some reason the "fake" device for automation is marked as DISABLED,
   // so white-list it.
   for (uint32_t i = 0; i < devices->count; i++) {
     if (devices->device[i]->type == CUBEB_DEVICE_TYPE_INPUT && // paranoia
         (devices->device[i]->state == CUBEB_DEVICE_STATE_ENABLED ||
          devices->device[i]->state == CUBEB_DEVICE_STATE_UNPLUGGED ||
          (devices->device[i]->state == CUBEB_DEVICE_STATE_DISABLED &&
+          devices->device[i]->friendly_name &&
           strcmp(devices->device[i]->friendly_name, "Sine source at 440 Hz") == 0)))
     {
       auto j = mDeviceNames->IndexOf(devices->device[i]->device_id);
       if (j != nsTArray<nsCString>::NoIndex) {
         // match! update the mapping
         (*mDeviceIndexes)[j] = i;
       } else {
         // new device, add to the array