diff --git a/once/install.sh b/once/install.sh
index 07559f1..23ecab4 100755
--- a/once/install.sh
+++ b/once/install.sh
@@ -21,15 +21,21 @@ else
 	mkdir -p "$SYSROOT"
 fi
 
+rm -f /etc/tarballs.sha256.tmp
+
 for tarball in /tarballs/*.tar.gz; do
 	echo @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 	echo extracting files from $tarball
 	echo ..................................................
 	tar -xpvf $tarball -C "$SYSROOT"
+	sha256sum $tarball >> /etc/tarballs.sha256.tmp
 	echo ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 	echo
 done
 
+rm -f /etc/tarballs.sha256
+sed 's@/tarballs/@@g' /etc/tarballs.sha256.tmp > /etc/tarballs.sha256
+
 /custom.sh
 
 echo