diff --git a/srcpkgs/isl/template b/srcpkgs/isl/template
index 7d8c2d59c41..82412424080 100644
--- a/srcpkgs/isl/template
+++ b/srcpkgs/isl/template
@@ -12,6 +12,11 @@ license="LGPL-2.1"
 distfiles="http://isl.gforge.inria.fr/isl-${version}.tar.bz2"
 checksum=f4b3dbee9712850006e44f0db2103441ab3d13b406f77996d1df19ee89d11fb4
 
+if [ -z "$CHROOT_READY" ]; then
+	CFLAGS="-I${XBPS_MASTERDIR}/usr/include"
+	LDFLAGS="-L${XBPS_MASTERDIR}/usr/lib"
+fi
+
 post_install() {
 	# Remove gdb python files.
 	rm -f ${DESTDIR}/usr/lib/*.py