diff --git a/update_psa b/update_psa
index 5e6382d..8063958 100755
--- a/update_psa
+++ b/update_psa
@@ -90,24 +90,24 @@ update() {
         revert_customer_repository ; exit 1
     fi
 
-    local files=$(changed_file_names)
-    local system_files=$(filter_system_files "$files") # conf/ini-files
+    local changed_files=$(changed_file_names)
+    local conf_ini_files=$(filter_conf_ini_files "$changed_files")
 
     # check if *.conf and/or *.ini-files have to md5-sum as denoted
     # in update.conf
-    if ! check_md5_for_changed_conf_and_ini_files "$system_files" ; then
+    if ! check_md5_for_changed_conf_and_ini_files "$conf_ini_files" ; then
         log_error "$func:${LINENO}: new customer files wrong"
         revert_customer_repository ; exit 1
     fi
     
     # copy *.conf and/or *.ini-files to their corresponding system-directories
-    if ! copy $system_files; then
+    if ! copy $conf_ini_files; then
         log_error "$func:${LINENO}: copy operation failed"
         revert_customer_repository ; exit 1
     fi
 
     # check if the opkg-command-file has been changed during 'git pull'
-    if grep -qE ".*opkg_commands.*?" <<< $files; then
+    if grep -qE ".*opkg_commands.*?" <<< $changed_files; then
         # read opkg_cmds: each line respresents an opkg-command
         readarray opkg_commands < <(cat $opkg_cmds_file)
         for opkg_c in "${opkg_commands[@]}"; do