Scp cannot handle file times before the Unix epoch

Native Linux filesystems have been able to store file timestamps before the Unix epoch, 1 Jan 1970, for some time now, due to use of 64-bit time_t.

Today I discovered that scp cannot transfer timestamps before the epoch. Here I copied a file which contains a scan of an old photo that I have timestamped back to the day it was sent:

-rw-r--r-- 1 me users 245768 Jan  1  1970 /tmp/1946-07-31-myrtle.pdf

By comparison, rsync does the right thing:

-rw-r--r-- 1 me users 245768 Jul 31  1946 /tmp/1946-07-31-myrtle.pdf

I suppose I could look into the scp protocol to discover why this is.