diff --git a/create_sympa_listdomain.sh b/create_sympa_listdomain.sh
index ef1d5fa..d0d2b67 100755
--- a/create_sympa_listdomain.sh
+++ b/create_sympa_listdomain.sh
@@ -392,9 +392,6 @@ fi
 
 # - if multiple listmasers where given in a blank separated list, we correct it here
 # -
-echo ""
-echo "SYMPA_LISTMASTER: $SYMPA_LISTMASTER"
-echo ""
 declare -a listmaster_arr=()
 for _listmaster in $SYMPA_LISTMASTER ; do
    listmaster_arr+=("$_listmaster")
@@ -408,7 +405,11 @@ for _listmaster in "${listmaster_arr[@]}" ; do
    else
       SYMPA_LISTMASTER="${SYMPA_LISTMASTER},$_listmaster"
    fi
-done
+SYMPA_LISTMASTER="$(echo $SYMPA_LISTMASTER | sed 's/\(.\)\1*/\1/g')"
+# Remove trailling ','
+SYMPA_LISTMASTER="${SYMPA_LISTMASTER%,}"
+# remove leading ','
+SYMPA_LISTMASTER=${SYMPA_LISTMASTER#,}
 
 
 if grep -e "^\s*listmaster" $SYMPA_MAIN_CONF_FILE > /dev/null 2>&1 ; then