--- firemake/headers.orig	2014-05-20 14:43:33.135642364 +0800
+++ firemake/headers	2014-05-20 14:43:44.118599465 +0800
@@ -16,7 +16,7 @@ case $PHASE in
 		$ECHO "install_headers:"
 
 		for HEADER in $HEADERS; do
-			$ECHO "	$INSTALL $HEADER \$(INCLUDEDIR) $INSTALL_USER $INSTALL_GROUP 0644"
+			$ECHO "	$INSTALL $HEADER \$(DESTDIR)\$(INCLUDEDIR) $INSTALL_USER $INSTALL_GROUP 0644"
 		done
 		$ECHO