--- isight-firmware-tools-1.6.orig/configure.ac
+++ isight-firmware-tools-1.6/configure.ac
@@ -24,8 +24,8 @@ AC_SUBST(IFT_LIBS)
 PKG_CHECK_MODULES(LOAD, [libusb])
 AC_SUBST(LOAD_CFLAGS)
 AC_SUBST(LOAD_LIBS)
-
-udevdir=${libdir}/udev
+PKG_PROG_PKG_CONFIG
+udevdir=$($PKG_CONFIG --variable=udevdir udev)
 AC_SUBST(udevdir)
 
 dnl GETTEXT
--- isight-firmware-tools-1.6.orig/src/Makefile.am
+++ isight-firmware-tools-1.6/src/Makefile.am
@@ -21,7 +21,7 @@ ift_load_SOURCES = udev.c load.c load.h
 ift_load_CFLAGS = $(IFT_CFLAGS) $(LOAD_CFLAGS) $(AM_CFLAGS)
 ift_load_LDADD = $(IFT_LIBS) $(LOAD_LIBS)
 
-rulesdir = ${sysconfdir}/udev/rules.d
+rulesdir = ${udevdir}/rules.d
 rules_DATA = isight.rules
 
 # AC_SUBST sucks