conflicting types for `statfs' on OSF1

 > uname -mprsv
OSF1 V5.1 1885 alpha alpha
 > gcc --version
gcc (GCC) 3.1
 > ./configure | & tee configure.log
    .
    .
    .
 > make | & tee make.log
    .
    .
    .
source='fsusage.c' object='fsusage.o' libtool=no  
depfile='.deps/fsusage.Po' tmpdepfile='.deps/fsusage.TPo'  depmode=gcc3 
/bin/sh ../depcomp  gcc -DLIBDIR=\"/usr/local/lib\" -DHAVE_CONFIG_H -I.. 
-I. -I../intl    -g -O2 -c -o fsusage.o `test -f fsusage.c || echo 
'./'`fsusage.c
In file included from fsusage.c:43:
/usr/include/sys/mount.h:636: conflicting types for `statfs'
/usr/include/sys/mount.h:636: a parameter list with an ellipsis can't 
match an empty parameter name list declaration
fsusage.c:36: previous declaration of `statfs'
*** Exit 1
Stop.
*** Exit 1
Stop.
*** Exit 1
Stop.
*** Exit 1
Stop.