Index: uspace/srv/net/dhcp/transport.c
===================================================================
--- uspace/srv/net/dhcp/transport.c	(revision 5a324d992b3382c26e5d9d448d8c857d73a4a6b4)
+++ uspace/srv/net/dhcp/transport.c	(revision b5f716bc90001ca89dfcaf04f82a2b4e1dd2e11e)
@@ -172,5 +172,5 @@
 	dhcp_transport_t *dt = (dhcp_transport_t *)arg;
 	void *msg;
-	size_t size;
+	size_t size = (size_t) -1;
 	int rc;
 
@@ -179,4 +179,6 @@
 		if (rc != EOK)
 			break;
+
+		assert(size != (size_t) -1);
 
 		dt->recv_cb(dt->cb_arg, msg, size);