diff --git a/templates/mailman-hyperkitty.py.j2 b/templates/mailman-hyperkitty.py.j2
index ca3aa5f..2286d3f 100644
--- a/templates/mailman-hyperkitty.py.j2
+++ b/templates/mailman-hyperkitty.py.j2
@@ -13,7 +13,7 @@
 # address will be used by Mailman to forward incoming emails to HyperKitty
 # for archiving. It does not need to be publicly available, in fact it's
 # better if it is not.
-base_url: http://localhost/mailman3/hyperkitty/
+base_url: http://localhost:15427/hyperkitty/
 
 # Shared API key, must be the identical to the value in HyperKitty's
 # settings.