diff --git a/docker/scripts/mininet/single_switch_mininet.py b/docker/scripts/mininet/single_switch_mininet.py
index 67f8035..3e2755b 100755
--- a/docker/scripts/mininet/single_switch_mininet.py
+++ b/docker/scripts/mininet/single_switch_mininet.py
@@ -42,9 +42,9 @@
 parser.add_argument('--pcap-dump', help='Dump packets on interfaces to pcap files',
                    action="store_true")
 parser.add_argument('--switch-config', help='simple_switch_CLI script to configure switch',
-                    type=str, action="store", required=False, default=False)
+                    type=str, action="store", required=False, default=None)
 parser.add_argument('--cli-message', help='Message to print before starting CLI',
-                    type=str, action="store", required=False, default=False)
+                    type=str, action="store", required=False, default=None)
 
 args = parser.parse_args()