--- a/dom/tests/mochitest/general/test_interfaces.html
+++ b/dom/tests/mochitest/general/test_interfaces.html
@@ -1373,17 +1373,17 @@ var interfaceNamesInGlobalScope =
     {name: "TVProgram", b2g: true, permission: ["tv"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "TVScanningStateChangedEvent", b2g: true, permission: ["tv"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "TVSource", b2g: true, permission: ["tv"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "TVTuner", b2g: true, permission: ["tv"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    {name: "U2F", release: false},
+    {name: "U2F", disabled: true},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "UDPMessageEvent", b2g: true, permission: ["udp-socket"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "UDPSocket", b2g: true, permission: ["udp-socket"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "UIEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "UndoManager",

--- a/dom/webidl/U2F.webidl
+++ b/dom/webidl/U2F.webidl
@@ -63,16 +63,17 @@ dictionary SignResponse {
     // From Error
     ErrorCode? errorCode;
     DOMString? errorMessage;
 };
 
 callback U2FRegisterCallback = void(RegisterResponse response);
 callback U2FSignCallback = void(SignResponse response);
 
+[Pref="security.webauth.u2f"]
 interface U2F {
   // These enumerations are defined in the FIDO U2F Javascript API under the
   // interface "ErrorCode" as constant integers, and also in the U2F.cpp file.
   // Any changes to these must occur in both locations.
   const unsigned short OK = 0;
   const unsigned short OTHER_ERROR = 1;
   const unsigned short BAD_REQUEST = 2;
   const unsigned short CONFIGURATION_UNSUPPORTED = 3;