diff --git a/sys/src/9/pc64/mkfile b/sys/src/9/pc64/mkfile
index d3f9e7e5f..696d8cbd7 100644
--- a/sys/src/9/pc64/mkfile
+++ b/sys/src/9/pc64/mkfile
@@ -85,11 +85,12 @@ install:V:	$p$CONF
 # copies generated by the rule below
 PCHEADERS=wifi.h uncached.h usbehci.h screen.h etherif.h ethermii.h mp.h io.h ahci.h
 
-&.h:	../pc/&.h
+REPCH=`{echo $PCHEADERS | sed 's/\.h//g; s/ /|/g'}
+^($REPCH)\.h:R:	'../pc/\1.h'
 	cp $prereq .
 
-PCFILES=`{../port/mkfilelist ../pc}
-^($PCFILES)\.$O:R:	'../pc/\1.c'
+REPCC=`{../port/mkfilelist ../pc}
+^($REPCC)\.$O:R:	'../pc/\1.c'
 	$CC $CFLAGS -I. -. ../pc/$stem1.c
 
 <../boot/bootmkfile