diff --git a/externs/cosmopolite.js b/externs/cosmopolite.js
index 2adc7d3..e7a86d1 100644
--- a/externs/cosmopolite.js
+++ b/externs/cosmopolite.js
@@ -55,6 +55,14 @@ Cosmopolite.typeSubjectLoose;
 function Cosmopolite(opt_urlPrefix, opt_namespace, opt_trackingID) {}
 
 
+/**
+ * @see https://www.cosmopolite.org/reference#uuid
+ * @return {string}
+ * @nosideeffects
+ */
+Cosmopolite.uuid = function() {};
+
+
 /**
  * @see https://www.cosmopolite.org/reference#shutdown
  */