diff --git a/README.md b/README.md
index 3a9d02c..b658a20 100644
--- a/README.md
+++ b/README.md
@@ -77,10 +77,9 @@ If `MF_DEBUG` is set to `1`, `miniflux-filter`  will print extra output to stdou
 
 | RC  | Description                     |
 | --- | ------------------------------- |
-| 1   | `$MF_FILTERLIST_FILE` not found |
+| 1   | `$MF_FILTERLIST` not set |
 | 2   | `$MF_AUTH_TOKEN` not set        |
 | 3   | `$MF_API_URL` not set           |
-| 4   | `$MF_FILTERLIST_FILE` is a dir  |
 | 5   | `jq` is not installed           |
 | 6   | `curl` is not installed         |
 | 7   | could not connect to `miniflux` |
diff --git a/filter.sh b/filter.sh
index c8f585b..636287d 100755
--- a/filter.sh
+++ b/filter.sh
@@ -5,8 +5,6 @@ if [[ $MF_DEBUG -eq 1 ]]; then
     printf "miniflux-filter - git.mgrote.net/mg/miniflux-filter\n"
 fi
 
-### datei mit filter ausdruecken
-MF_FILTERLIST_FILE="${MF_FILTERLIST_FILE:=/data/filter.txt}"
 ### wartezeit zwischen durchlaeufen
 MF_SLEEP="${MF_SLEEP:=30}"
 ### MF_DEBUG output
@@ -84,17 +82,11 @@ function check_vars {
         echo [ERROR] '"$MF_API_URL"' not set.
         exit 3
     fi
-    # prüfe ob filter-datei ein ordner ist
-    # kann bei einem falschen bind-mount passieren
-    if [[ -d "$MF_FILTERLIST_FILE" ]]; then
-        # shellcheck disable=SC2102
-        echo [ERROR] "$MF_FILTERLIST_FILE" is a directory!
-        exit 4
-    fi
     # pruefe ob filter-datei NICHT existiert
-    if [[ ! -e "$MF_FILTERLIST_FILE" ]]; then
+    if [[ -z "${MF_FILTERLIST}" ]]; then
+        # shellcheck disable=SC2016
         # shellcheck disable=SC2102
-        echo [ERROR] "$MF_FILTERLIST_FILE" not readable!
+        echo [ERROR] '"$MF_FILTERLIST"' not set.
         exit 1
     fi
 }
@@ -142,11 +134,10 @@ function check_api_connectivity {
 function debug_output {
     if [[ $MF_DEBUG -eq 1 ]]; then
         echo -----------------------------------------------------
-        echo [DEBUG] Filterlist-File: "$MF_FILTERLIST_FILE"
         echo [DEBUG] Sleep-Intervall: "$MF_SLEEP"
         echo [DEBUG] Auth-Token: "$MF_AUTH_TOKEN"
         echo [DEBUG] MF-Url: "$MF_API_URL"
-        echo [DEBUG] Anzahl Filter: "$(wc -l < "$MF_FILTERLIST_FILE")"
+        echo [DEBUG] Anzahl Filter: "$(wc -l < "$MF_FILTERLIST")"
         echo -----------------------------------------------------
     fi
 }
@@ -165,7 +156,7 @@ function get_unread_entries {
 }
 function filter_entries {
     echo "[INFO] Filtering entries..."
-    # fuer jede Zeile in $MF_FILTERLIST_FILE
+    # fuer jede Zeile in $MF_FILTERLIST
     while read -r line; do
         if [[ $MF_DEBUG -eq 1 ]]; then
             echo "[DEBUG] set search values"
@@ -194,7 +185,7 @@ function filter_entries {
                 marked_entries+=" $(echo "$unread_entries" | jq --arg url "$url" --arg suchbegriff "$suchbegriff" '.entries[] | select(.feed.site_url | ascii_downcase | contains($url)) | select(.content | ascii_downcase | contains($suchbegriff)) | .id' )"
             fi
         fi
-    done < "$MF_FILTERLIST_FILE"
+    done < "$MF_FILTERLIST"
 }
 function mark_as_read {
     # https://stackoverflow.com/questions/3869072/test-for-non-zero-length-string-in-bash-n-var-or-var