--- makefile.orig	Sun Sep 25 03:26:37 1994
+++ makefile	Sun Sep 25 03:26:45 1994
@@ -235,7 +235,7 @@
 parse.o: zoofns.h zooio.h
 portable.o: /usr/include/stdio.h assert.h debug.h machine.h options.h
 portable.o: portable.h various.h zoo.h zoofns.h zooio.h
-prterror.o: /usr/include/stdio.h /usr/include/varargs.h options.h various.h
+prterror.o: /usr/include/stdio.h /usr/include/unistd.h options.h various.h
 prterror.o: zoofns.h zooio.h
 sysv.o: /usr/include/sys/stat.h /usr/include/sys/types.h /usr/include/time.h
 sysv.o: nixmode.i nixtime.i