diff --git a/boards/native/drivers/native-uart0.c b/boards/native/drivers/native-uart0.c
index 14e9bd64b1f149ea5f1a02ca38b519ba9c16a786..8b0b8e197587f8c731702666441ab71f1a536081 100644
--- a/boards/native/drivers/native-uart0.c
+++ b/boards/native/drivers/native-uart0.c
@@ -92,7 +92,7 @@ void *get_in_addr(struct sockaddr *sa)
 int init_tcp_socket(char *tcpport)
 {
     struct addrinfo hints, *info, *p;
-    int i, s;
+    int i, s = -1;
     if (tcpport == NULL) {
         tcpport = UART_TCPPORT;
     }