diff --git a/include/lte/lte_lwm2m.h b/include/lte/lte_lwm2m.h
index b557c8bc5b..dd926ca899 100644
--- a/include/lte/lte_lwm2m.h
+++ b/include/lte/lte_lwm2m.h
@@ -227,7 +227,7 @@ struct lwm2mstub_serverinfo_s
   bool bootstrap;
   bool nonip;
   int security_mode;
-  unsigned short lifetime;
+  uint32_t lifetime;
   char server_uri[LWM2MSTUB_MAX_SERVER_NAME];
   char device_id[LWM2MSTUB_MAX_DEVID];
   char security_key[LWM2MSTUB_MAX_SEQKEY];
diff --git a/lte/alt1250/alt1250_atcmd.c b/lte/alt1250/alt1250_atcmd.c
index bde0154749..2a05810cc0 100644
--- a/lte/alt1250/alt1250_atcmd.c
+++ b/lte/alt1250/alt1250_atcmd.c
@@ -672,7 +672,7 @@ int lwm2mstub_send_bscreateobj1(FAR struct alt1250_s *dev,
       FAR struct lwm2mstub_serverinfo_s *info)
 {
   snprintf((char *)dev->tx_buff, _TX_BUFF_SIZE,
-    "AT%%LWM2MBSCMD=\"CREATE\",1,0,0,0,1,%u,%s\r", info->lifetime,
+    "AT%%LWM2MBSCMD=\"CREATE\",1,0,0,0,1,%lu,%s\r", info->lifetime,
       info->nonip ? ",7,\"N\",22,\"N\"" : "");
 
   return send_internal_at_command(dev, container, usockid, proc, arg, ures);