diff --git a/edge.c b/edge.c
index 876468a..9e5a7d7 100644
--- a/edge.c
+++ b/edge.c
@@ -287,7 +287,7 @@ static int setOption(int optkey, char *optargument, n2n_priv_config_t *ec, n2n_e
     }
 
   case 'i': /* supernode registration interval */
-    conf->register_interval = atoi(optarg);
+    conf->register_interval = atoi(optargument);
     break;
 
 #if defined(N2N_CAN_NAME_IFACE)