diff --git a/templates/connect b/templates/connect
index 33edb69..63c64d0 100644
--- a/templates/connect
+++ b/templates/connect
@@ -18,6 +18,8 @@
               local_bind_port  = [[ $upstream.local_bind_port ]]
       [[- else if and (has $ "connect_services") (has $.connect_services $upstream.destination_name) (has (index $.connect_services $upstream.destination_name) "port") ]]
               local_bind_port  = [[ (index $.connect_services $upstream.destination_name).port ]]
+      [[- else ]]
+        [[- test.Fail (printf "Service %s has no local_bind_port defined" $upstream.destination_name) ]]
       [[- end ]]
               # Work arround, see https://github.com/hashicorp/nomad/issues/18538
               destination_type = "service"