diff --git a/mozilla/extensions/wallet/src/nsPasswordManager.cpp b/mozilla/extensions/wallet/src/nsPasswordManager.cpp
index df4ef91cd2d..9d2de937d71 100644
--- a/mozilla/extensions/wallet/src/nsPasswordManager.cpp
+++ b/mozilla/extensions/wallet/src/nsPasswordManager.cpp
@@ -263,6 +263,6 @@ nsPasswordManager::FindPasswordEntry
 
 NS_IMETHODIMP nsPasswordManager::AddReject(const nsACString& host)
 {
-  return ::SINGSIGN_AddReject(host.get());
+  return ::SINGSIGN_AddReject(PromiseFlatCString(host).get());
 }