diff --git a/resources/static/shared/network.js b/resources/static/shared/network.js
index 9a3f2ce5584ba56639f7f283ff8cdf4632a87d0c..333f8a9d339dd6a92df17b2e87f3830773459fa3 100644
--- a/resources/static/shared/network.js
+++ b/resources/static/shared/network.js
@@ -121,7 +121,8 @@ BrowserID.Network = (function() {
         url: "/wsapi/auth_with_assertion",
         data: {
           email: email,
-          assertion: assertion
+          assertion: assertion,
+          ephemeral: !storage.usersComputer.confirmed(email)
         },
         success: handleAuthenticationResponse.curry("assertion", onComplete, onFailure),
         error: onFailure