diff --git a/gestion/gen_confs/firewall4.py b/gestion/gen_confs/firewall4.py
index 4cec028a..66f4e3e1 100755
--- a/gestion/gen_confs/firewall4.py
+++ b/gestion/gen_confs/firewall4.py
@@ -340,7 +340,7 @@ class firewall_base(object) :
             bl_hard_ips = set(
                 str(ip) for ips in
                 [
-                    machine['ipHostNumber'] for machine in self.blacklisted_machines() if reduce(lambda x,y: x or y, ( ip.value in netaddr.IPNetwork(n) for n in  config.NETs['all'] for ip in machine['ipHostNumber']))
+                    machine['ipHostNumber'] for machine in self.blacklisted_machines() if machine['ipHostNumber'] and reduce(lambda x,y: x or y, ( ip.value in netaddr.IPNetwork(n) for n in  config.NETs['all'] for ip in machine['ipHostNumber']))
                     if set([bl.value['type'] for bl in machine.blacklist_actif() ]).intersection(blacklist_sanctions)
                 ]
                 for ip in ips
@@ -755,7 +755,7 @@ class firewall_komaz(firewall_base_routeur):
             bl_soft_ips = set(
                 str(ip) for ips in
                 [
-                    machine['ipHostNumber'] for machine in self.blacklisted_machines() if reduce(lambda x,y: x or y, ( ip.value in netaddr.IPNetwork(n) for n in  config.NETs['all'] for ip in machine['ipHostNumber']))
+                    machine['ipHostNumber'] for machine in self.blacklisted_machines() if machine['ipHostNumber'] and reduce(lambda x,y: x or y, ( ip.value in netaddr.IPNetwork(n) for n in  config.NETs['all'] for ip in machine['ipHostNumber']))
                     if set([bl.value['type'] for bl in machine.blacklist_actif() ]).intersection(blacklist_sanctions_soft)
                 ]
                 for ip in ips