nsupdate TSIG error?

[@lbutlr]

I am invoking nsupdate with 

nsupdate -k /etc/namedb/admin.key

When I make the changes to a domain and `send` I get, 

; TSIG error with server: expected a TSIG or SIG(0)
update failed: REFUSED

/etc/namedb is an alias to /usr/local/etc/namedb/ and admin.jet contains:

# cat admin.key
key "rndc-key" {
       algorithm hmac-sha256;
       secret "stuff=";
};

This is the same key that is in named.conf.

(I am trying to reduce the TTL on the NS servers in preparation for moving the domain to be locally hosted, so right now the DNS servers it is pointing to are not under my control).

Here's the whole thing wrong show to send:

> zone example.net
> show
Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;example.net.            IN      SOA

> update delete example.net. IN NS ns1.example.com.
> update add example.net. 3600 IN NS ns1.example.com.
> show
Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;example.net.            IN      SOA

;; UPDATE SECTION:
example.net.     0       NONE    NS      ns1.example.com.
example.net.     3600    IN      NS      ns1.example.com.

> send
; TSIG error with server: expected a TSIG or SIG(0)
update failed: REFUSED
>

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