--- a/media/mtransport/nricectx.cpp
+++ b/media/mtransport/nricectx.cpp
@@ -207,17 +207,17 @@ nsresult NrIceStunServer::ToNicerStunStr
   int r;
 
   memset(server, 0, sizeof(nr_ice_stun_server));
   if (transport_ == kNrIceTransportUdp) {
     server->transport = IPPROTO_UDP;
   } else if (transport_ == kNrIceTransportTcp) {
     server->transport = IPPROTO_TCP;
   } else {
-    MOZ_ASSERT(false);
+    MOZ_MTLOG(ML_ERROR, "Unsupported STUN server transport: " << transport_);
     return NS_ERROR_FAILURE;
   }
 
   if (has_addr_) {
     r = nr_praddr_to_transport_addr(&addr_, &server->u.addr,
                                     server->transport, 0);
     if (r) {
       return NS_ERROR_FAILURE;