--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -443,17 +443,17 @@ pref("media.getusermedia.noise", 1);
 pref("media.getusermedia.agc_enabled", false);
 pref("media.getusermedia.agc", 1);
 // capture_delay: Adjustments for OS-specific input delay (lower bound)
 // playout_delay: Adjustments for OS-specific AudioStream+cubeb+output delay (lower bound)
 // full_duplex: enable cubeb full-duplex capture/playback
 #if defined(XP_MACOSX)
 pref("media.peerconnection.capture_delay", 50);
 pref("media.getusermedia.playout_delay", 10);
-pref("media.navigator.audio.full_duplex", false);
+pref("media.navigator.audio.full_duplex", true);
 #elif defined(XP_WIN)
 pref("media.peerconnection.capture_delay", 50);
 pref("media.getusermedia.playout_delay", 40);
 pref("media.navigator.audio.full_duplex", true);
 #elif defined(ANDROID)
 pref("media.peerconnection.capture_delay", 100);
 pref("media.getusermedia.playout_delay", 100);
 pref("media.navigator.audio.full_duplex", false);