--- a/netwerk/test/unit/test_udp_multicast.js
+++ b/netwerk/test/unit/test_udp_multicast.js
@@ -12,17 +12,16 @@ const ADDRESS_TEST1 = "224.0.0.200";
 const ADDRESS_TEST2 = "224.0.0.201";
 const ADDRESS_TEST3 = "224.0.0.202";
 const ADDRESS_TEST4 = "224.0.0.203";
 
 const TIMEOUT = 2000;
 
 const ua = Cc["@mozilla.org/network/protocol;1?name=http"]
            .getService(Ci.nsIHttpProtocolHandler).userAgent;
-const isWinXP = ua.indexOf("Windows NT 5.1") != -1;
 
 var gConverter;
 
 function run_test() {
   setup();
   run_next_test();
 }
 
@@ -83,32 +82,27 @@ add_test(() => {
   let socket = createSocketAndJoin(ADDRESS_TEST2);
   socket.multicastLoopback = false;
   sendPing(socket, ADDRESS_TEST2).then(
     () => do_throw("Loopback disabled, but still got a packet"),
     run_next_test
   );
 });
 
-// The following multicast interface test doesn't work on Windows XP, as it
-// appears to allow packets no matter what address is given, so we'll skip the
-// test there.
-if (!isWinXP) {
-  add_test(() => {
-    do_print("Changing multicast interface");
-    let socket = createSocketAndJoin(ADDRESS_TEST3);
-    socket.multicastInterface = "127.0.0.1";
-    sendPing(socket, ADDRESS_TEST3).then(
-      () => do_throw("Changed interface, but still got a packet"),
-      run_next_test
-    );
-  });
+add_test(() => {
+  do_print("Changing multicast interface");
+  let socket = createSocketAndJoin(ADDRESS_TEST3);
+  socket.multicastInterface = "127.0.0.1";
+  sendPing(socket, ADDRESS_TEST3).then(
+    () => do_throw("Changed interface, but still got a packet"),
+    run_next_test
+  );
+});
 
 add_test(() => {
   do_print("Leaving multicast group");
   let socket = createSocketAndJoin(ADDRESS_TEST4);
   socket.leaveMulticast(ADDRESS_TEST4);
   sendPing(socket, ADDRESS_TEST4).then(
     () => do_throw("Left group, but still got a packet"),
     run_next_test
   );
 });
-}

--- a/netwerk/test/unit/xpcshell.ini
+++ b/netwerk/test/unit/xpcshell.ini
@@ -338,25 +338,21 @@ skip-if = os == "android"
 skip-if = os != "win"
 [test_synthesized_response.js]
 [test_udp_multicast.js]
 [test_redirect_history.js]
 [test_reply_without_content_type.js]
 [test_websocket_offline.js]
 [test_be_conservative.js]
 # The local cert service used by this test is not currently shipped on Android
-# Disabled on XP in bug 1190674 for intermittent failures
-skip-if = os == "android" || (os == "win" && (os_version == "5.1" || os_version == "5.2"))
-reason = bug 1190674
+skip-if = os == "android"
 firefox-appdir = browser
 [test_tls_server.js]
 # The local cert service used by this test is not currently shipped on Android
-# Disabled on XP in bug 1190674 for intermittent failures
-skip-if = os == "android" || (os == "win" && (os_version == "5.1" || os_version == "5.2"))
-reason = bug 1190674
+skip-if = os == "android"
 firefox-appdir = browser
 [test_tls_server_multiple_clients.js]
 # The local cert service used by this test is not currently shipped on Android
 skip-if = os == "android"
 [test_1073747.js]
 [test_safeoutputstream_append.js]
 [test_suspend_channel_before_connect.js]
 [test_inhibit_caching.js]