--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -497,17 +497,17 @@ pref("media.peerconnection.ice.relay_onl
 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);
 pref("media.peerconnection.ice.trickle_grace_period", 5000);
 pref("media.peerconnection.ice.no_host", false);
 pref("media.peerconnection.ice.default_address_only", false);
 pref("media.peerconnection.ice.proxy_only", false);
-pref("media.peerconnection.rtpsourcesapi.enabled", true);
+pref("media.peerconnection.rtpsourcesapi.enabled", false);
 
 // These values (aec, agc, and noise) are from media/webrtc/trunk/webrtc/common_types.h
 // kXxxUnchanged = 0, kXxxDefault = 1, and higher values are specific to each
 // setting (for Xxx = Ec, Agc, or Ns).  Defaults are all set to kXxxDefault here.
 pref("media.peerconnection.turn.disable", false);
 #if defined(MOZ_WEBRTC_HARDWARE_AEC_NS)
 pref("media.getusermedia.aec_enabled", false);
 pref("media.getusermedia.noise_enabled", false);