diff --git a/backup.sh b/backup.sh
index c54f3b0..763759c 100755
--- a/backup.sh
+++ b/backup.sh
@@ -27,7 +27,7 @@
 
 # backup repositories
 repoFile="${backupDir}/repositories/${currentDate}.tbz2"
-tar -cj data/repositories -f ${repoFile}
+tar -c -I pbzip2 data/repositories -f ${repoFile}
 
 # backup config files
 tar -cj data/conf -f "${backupDir}/conf/${currentDate}.tbz2"