--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -360,16 +360,19 @@ pref("media.apple.mp4.enabled", true);
 pref("media.gmp.storage.version.expected", 1);
 
 // Filter what triggers user notifications.
 // See DecoderDoctorDocumentWatcher::ReportAnalysis for details.
 pref("media.decoder-doctor.notifications-allowed", "MediaWidevineNoWMFNoSilverlight");
 // Whether we report partial failures.
 pref("media.decoder-doctor.verbose", false);
 
+// Whether to suspend decoding of videos in background tabs.
+pref("media.suspend-bkgnd-video.enabled", true);
+
 #ifdef MOZ_WEBRTC
 pref("media.navigator.enabled", true);
 pref("media.navigator.video.enabled", true);
 pref("media.navigator.load_adapt", true);
 pref("media.navigator.load_adapt.measure_interval",1000);
 pref("media.navigator.load_adapt.avg_seconds",3);
 pref("media.navigator.load_adapt.high_load","0.90");
 pref("media.navigator.load_adapt.low_load","0.40");