diff --git a/example/defaults.conf b/example/defaults.conf
index b1fbfbb..2708b18 100644
--- a/example/defaults.conf
+++ b/example/defaults.conf
@@ -111,3 +111,4 @@
   enable_pcap: false
   airplane_t_on_ms: -1
   airplane_t_off_ms: -1
+  num_carriers: 1