diff --git a/browser/base/content/test/general/browser_misused_characters_in_strings.js b/browser/base/content/test/general/browser_misused_characters_in_strings.js
index f62612df780c..9b3c598ffaf9 100644
--- a/browser/base/content/test/general/browser_misused_characters_in_strings.js
+++ b/browser/base/content/test/general/browser_misused_characters_in_strings.js
@@ -100,10 +100,6 @@ let gWhitelist = [{
     file: "netErrorApp.dtd",
     key: "securityOverride.warningContent",
     type: "single-quote"
-  }, {
-    file: "sync.properties",
-    key: "client.name2",
-    type: "apostrophe"
   }
 ];
 
diff --git a/services/sync/locales/en-US/sync.properties b/services/sync/locales/en-US/sync.properties
index 23b71916c830..3d83ac94488d 100644
--- a/services/sync/locales/en-US/sync.properties
+++ b/services/sync/locales/en-US/sync.properties
@@ -3,7 +3,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 # %1: the user name (Ed), %2: the app name (Firefox), %3: the operating system (Android)
-client.name2 = %1$S's %2$S on %3$S
+client.name2 = %1$S’s %2$S on %3$S
 
 # %S is the date and time at which the last sync successfully completed
 lastSync2.label = Last sync: %S
diff --git a/services/sync/tests/unit/head_helpers.js b/services/sync/tests/unit/head_helpers.js
index 3b09659b9760..dc3ec5a04042 100644
--- a/services/sync/tests/unit/head_helpers.js
+++ b/services/sync/tests/unit/head_helpers.js
@@ -4,6 +4,7 @@
 Cu.import("resource://services-common/async.js");
 Cu.import("resource://testing-common/services/common/utils.js");
 Cu.import("resource://testing-common/PlacesTestUtils.jsm");
+Cu.import("resource://services-sync/util.js");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 XPCOMUtils.defineLazyGetter(this, 'SyncPingSchema', function() {
@@ -390,3 +391,12 @@ function sync_engine_and_validate_telem(engine, allowErrorPings, onError) {
     }
   });
 }
+
+// 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).
+Utils.getDefaultDeviceName = function() {
+  return "Test device name";
+};
+
+