--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -467,17 +467,17 @@ pref("media.peerconnection.video.min_bit
 pref("media.peerconnection.video.start_bitrate", 0);
 pref("media.peerconnection.video.max_bitrate", 0);
 pref("media.peerconnection.video.min_bitrate_estimate", 0);
 pref("media.navigator.audio.fake_frequency", 1000);
 pref("media.navigator.permission.disabled", false);
 pref("media.peerconnection.simulcast", true);
 pref("media.peerconnection.default_iceservers", "[]");
 pref("media.peerconnection.ice.loopback", false); // Set only for testing in offline environments.
-pref("media.peerconnection.ice.tcp", false);
+pref("media.peerconnection.ice.tcp", true);
 pref("media.peerconnection.ice.tcp_so_sock_count", 0); // Disable SO gathering
 pref("media.peerconnection.ice.link_local", false); // Set only for testing IPV6 in networks that don't assign IPV6 addresses
 pref("media.peerconnection.ice.force_interface", ""); // Limit to only a single interface
 pref("media.peerconnection.ice.relay_only", false); // Limit candidates to TURN
 pref("media.peerconnection.use_document_iceservers", true);
 pref("media.peerconnection.identity.enabled", true);
 pref("media.peerconnection.identity.timeout", 10000);
 pref("media.peerconnection.ice.stun_client_maximum_transmits", 7);