diff --git a/contrib/backup/functions b/contrib/backup/functions
index e3d807199..164fdd4d5 100644
--- a/contrib/backup/functions
+++ b/contrib/backup/functions
@@ -40,7 +40,14 @@ function backup_dir_create () {
 
 function backup_files () {
   echo "creating file backup..."
-  tar -czf ${BACKUP_DIR}/${TIMESTAMP}_zammad_files.tar.gz ${ZAMMAD_DIR}
+  SRC="${ZAMMAD_DIR}"
+  ARGS=""
+  # remove leading "/" to suppress the tar warning
+  if [[ "${ZAMMAD_DIR}" =~ ^/ ]]; then
+    SRC="${ZAMMAD_DIR:1}"
+    ARGS="-C /"
+  fi
+  tar ${ARGS} -czf ${BACKUP_DIR}/${TIMESTAMP}_zammad_files.tar.gz ${SRC}
   ln -sfn ${BACKUP_DIR}/${TIMESTAMP}_zammad_files.tar.gz ${BACKUP_DIR}/latest_zammad_files.tar.gz
 }