diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 8f6a1781b2e..9f41f33d27a 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1221,3 +1221,9 @@ pref("dom.identity.enabled", false);
 
 // Override the Gecko-default value of false for Firefox.
 pref("plain_text.wrap_long_lines", true);
+
+#ifndef RELEASE_BUILD
+// Enable Web Audio for Firefox Desktop in Nightly and Aurora
+pref("media.webaudio.enabled", true);
+#endif
+
diff --git a/content/media/webaudio/test/test_AudioContext.html b/content/media/webaudio/test/test_AudioContext.html
index c5c1eb65a4b..34d1e940f1c 100644
--- a/content/media/webaudio/test/test_AudioContext.html
+++ b/content/media/webaudio/test/test_AudioContext.html
@@ -11,14 +11,6 @@
 
 SimpleTest.waitForExplicitFinish();
 addLoadEvent(function() {
-  ok(!window.AudioContext, "AudioContext should be hidden behind a pref");
-  var accessThrows = false;
-  try {
-    new AudioContext();
-  } catch (e) {
-    accessThrows = true;
-  }
-  ok(accessThrows, "AudioContext should be hidden behind a pref");
   SpecialPowers.setBoolPref("media.webaudio.enabled", true);
   var ac = new AudioContext();
   ok(ac, "Create a AudioContext object");