diff --git a/services/sync/modules/util.js b/services/sync/modules/util.js
index 4dfcfb762513..3dae9ac6e247 100644
--- a/services/sync/modules/util.js
+++ b/services/sync/modules/util.js
@@ -592,7 +592,7 @@ this.Utils = {
       // 'device' is defined on unix systems
       Cc["@mozilla.org/system-info;1"].getService(Ci.nsIPropertyBag2).get("device") ||
       // hostname of the system, usually assigned by the user or admin
-      Cc["@mozilla.org/system-info;1"].getService(Ci.nsIPropertyBag2).get("host") ||
+      Cc["@mozilla.org/network/dns-service;1"].getService(Ci.nsIDNSService).myHostName ||
       // fall back on ua info string
       Cc["@mozilla.org/network/protocol;1?name=http"].getService(Ci.nsIHttpProtocolHandler).oscpu;
 
diff --git a/services/sync/tests/unit/head_helpers.js b/services/sync/tests/unit/head_helpers.js
index df0013a69204..ebb297e90d1e 100644
--- a/services/sync/tests/unit/head_helpers.js
+++ b/services/sync/tests/unit/head_helpers.js
@@ -490,6 +490,8 @@ function promiseNextTick() {
 // Avoid an issue where `client.name2` containing unicode characters causes
 // a number of tests to fail, due to them assuming that we do not need to utf-8
 // encode or decode data sent through the mocked server (see bug 1268912).
+// We stash away the original implementation so test_utils_misc.js can test it.
+Utils._orig_getDefaultDeviceName = Utils.getDefaultDeviceName;
 Utils.getDefaultDeviceName = function() {
   return "Test device name";
 };
diff --git a/services/sync/tests/unit/test_utils_misc.js b/services/sync/tests/unit/test_utils_misc.js
new file mode 100644
index 000000000000..e14fa0e547e0
--- /dev/null
+++ b/services/sync/tests/unit/test_utils_misc.js
@@ -0,0 +1,29 @@
+_("Misc tests for utils.js");
+
+add_test(function test_default_device_name() {
+  // Note that head_helpers overrides getDefaultDeviceName - this test is
+  // really just to ensure the actual implementation is sane - we can't
+  // really check the value it uses is correct.
+  // We are just hoping to avoid a repeat of bug 1369285.
+  let def = Utils._orig_getDefaultDeviceName(); // make sure it doesn't throw.
+  _("default value is " + def);
+  ok(def.length > 0);
+
+  // This is obviously tied to the implementation, but we want early warning
+  // if any of these things fail.
+  // We really want one of these 2 to provide a value.
+  let hostname = Cc["@mozilla.org/system-info;1"].getService(Ci.nsIPropertyBag2).get("device") ||
+                 Cc["@mozilla.org/network/dns-service;1"].getService(Ci.nsIDNSService).myHostName;
+  _("hostname is " + hostname);
+  ok(hostname.length > 0);
+  // the hostname should be in the default.
+  ok(def.includes(hostname));
+  // We expect the following to work as a fallback to the above.
+  let fallback = Cc["@mozilla.org/network/protocol;1?name=http"].getService(Ci.nsIHttpProtocolHandler).oscpu;
+  _("UA fallback is " + fallback);
+  ok(fallback.length > 0);
+  // the fallback should not be in the default
+  ok(!def.includes(fallback));
+
+  run_next_test();
+});
diff --git a/services/sync/tests/unit/xpcshell.ini b/services/sync/tests/unit/xpcshell.ini
index 8612834708e7..369751c9de97 100644
--- a/services/sync/tests/unit/xpcshell.ini
+++ b/services/sync/tests/unit/xpcshell.ini
@@ -30,6 +30,7 @@ support-files =
 [test_utils_json.js]
 [test_utils_lock.js]
 [test_utils_makeGUID.js]
+[test_utils_misc.js]
 [test_utils_notify.js]
 [test_utils_passphrase.js]