diff --git a/pgmon.py b/pgmon.py
index e1113eb..1cb2749 100755
--- a/pgmon.py
+++ b/pgmon.py
@@ -385,7 +385,7 @@ class Server:
             try:
                 (key, args_str) = req_csv.split(',', 1)
                 args_dict = {}
-                if args_str!= "":
+                if args_str is not None and args_str != "":
                     for (k, v) in [a.split('=', 1) for a in args_str.split(';')]:
                         args_dict[k] = v
             except socket.timeout:
diff --git a/pgmon_userparameter.conf b/pgmon_userparameter.conf
index d6ba38a..1850a4b 100644
--- a/pgmon_userparameter.conf
+++ b/pgmon_userparameter.conf
@@ -1 +1 @@
-UserParameter=pgmon[*],/usr/local/bin/pgmon.py -c /etc/zabbix/pgmon.cfg -a "$1"
+UserParameter=pgmon[*],/usr/local/bin/pgmon.py -c /etc/zabbix/pgmon.cfg -k "$1" -a "$2"