diff --git a/services/sync/tests/unit/head_appinfo.js.in b/services/sync/tests/unit/head_appinfo.js.in
index 8fa133ae0e8f..f7583c86e3dd 100644
--- a/services/sync/tests/unit/head_appinfo.js.in
+++ b/services/sync/tests/unit/head_appinfo.js.in
@@ -71,3 +71,9 @@ let DISABLE_TESTS_BUG_604565 = false;
 DISABLE_TESTS_BUG_604565 = true;
 #endif
 #endif
+
+// test_jpakeclient.js produces random failures on Windows 7
+let DISABLE_TESTS_BUG_618233 = false;
+#ifdef XP_WIN
+DISABLE_TESTS_BUG_618233 = true;
+#endif
diff --git a/services/sync/tests/unit/test_jpakeclient.js b/services/sync/tests/unit/test_jpakeclient.js
index 4ba449f5aaf1..a64050f9171f 100644
--- a/services/sync/tests/unit/test_jpakeclient.js
+++ b/services/sync/tests/unit/test_jpakeclient.js
@@ -112,6 +112,9 @@ const DATA = {"msg": "eggstreamly sekrit"};
 const POLLINTERVAL = 50;
 
 function run_test() {
+  if (DISABLE_TESTS_BUG_618233)
+    return;
+
   Svc.Prefs.set("jpake.serverURL", "http://localhost:8080/");
   Svc.Prefs.set("jpake.pollInterval", POLLINTERVAL);
   Svc.Prefs.set("jpake.maxTries", 5);