--- a/toolkit/content/widgets/videocontrols.xml
+++ b/toolkit/content/widgets/videocontrols.xml
@@ -1414,16 +1414,17 @@
                       elem.addEventListener(eventName, boundFunc, false);
                     }
 
                     addListener(this.muteButton, "command", this.toggleMute);
                     addListener(this.playButton, "command", this.togglePause);
                     addListener(this.fullscreenButton, "command", this.toggleFullscreen);
                     addListener(this.clickToPlay, "click", this.clickToPlayClickHandler);
                     addListener(this.controlsSpacer, "click", this.clickToPlayClickHandler);
+                    addListener(this.controlsSpacer, "dblclick", this.toggleFullscreen);
 
                     if (this.isAudioOnly) {
                       this.controlBar.classList.add("audio");
                     } else {
                       addListener(this.muteButton, "mouseover", this.onVolumeMouseInOut);
                       addListener(this.muteButton, "mouseout", this.onVolumeMouseInOut);
                       addListener(this.volumeStack, "mouseover", this.onVolumeMouseInOut);
                       addListener(this.volumeStack, "mouseout", this.onVolumeMouseInOut);