diff --git a/ethsock.c b/ethsock.c
index c1674d4..0372b59 100644
--- a/ethsock.c
+++ b/ethsock.c
@@ -21,11 +21,6 @@
 #endif
 #endif
 
-#ifndef MIN
-#define MIN(a, b) ((a) < (b) ? (a) : (b))
-#endif
-
-
 struct ethsock
 {
 	const char *intf;
diff --git a/nmrp.c b/nmrp.c
index ff4aeb7..a374c6c 100644
--- a/nmrp.c
+++ b/nmrp.c
@@ -213,16 +213,20 @@ static int msg_ntoh(struct nmrp_msg *msg)
 
 static void *msg_opt_data(struct nmrp_msg *msg, int type, uint16_t *len)
 {
+	static char buf[128];
 	struct nmrp_opt *opt = msg->opts;
 	int remaining = msg->len - NMRP_HDR_LEN;
 
+	memset(buf, 0, sizeof(buf));
+
 	while (remaining > 0) {
 		if (opt->type == type) {
 			if (opt->len == NMRP_OPT_LEN) {
 				return NULL;
 			}
 			*len = opt->len - NMRP_OPT_LEN;
-			return (char*)&opt->val;
+			memcpy(buf, &opt->val, MIN(*len, sizeof(buf)-1));
+			return buf;
 		}
 
 		remaining -= opt->len;
diff --git a/nmrpd.h b/nmrpd.h
index 0eabf26..cf5138d 100644
--- a/nmrpd.h
+++ b/nmrpd.h
@@ -49,6 +49,10 @@
 #include <windows.h>
 #endif
 
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
 enum nmrp_op {
 	NMRP_UPLOAD_FW = 0,
 	NMRP_UPLOAD_ST = 1,