'errno' undefined?

I get the following when building cvs:

gcc -I../../include -O2 -g -Wall -Wmissing-prototypes
-Wmissing-declarations -c pqformat.c -o pqformat.o
pqformat.c: In function `pq_endmessage':
pqformat.c:219: `errno' undeclared (first use in this function)
pqformat.c:219: (Each undeclared identifier is reported only once
pqformat.c:219: for each function it appears in.)
make: *** [pqformat.o] Error 1

Any ideas?

----------------------------------------------------------------
Philip Warner | __---_____
Albatross Consulting Pty. Ltd. |----/ - \
(A.C.N. 008 659 498) | /(@) ______---_
Tel: (+61) 0500 83 82 81 | _________ \
Fax: (+61) 0500 83 82 82 | ___________ |
Http://www.rhyme.com.au | / \|
| --________--
PGP key available upon request, | /
and from pgp5.ai.mit.edu:11371 |/