diff --git a/util/tube.c b/util/tube.c
index dc6e3c2e7..8ff474b87 100644
--- a/util/tube.c
+++ b/util/tube.c
@@ -363,7 +363,11 @@ int tube_read_msg(struct tube* tube, uint8_t** buf, uint32_t* len,
 		}
 		d += r;
 	}
-	log_assert(*len < 65536*2);
+	if (*len >= 65536*2) {
+	    log_err("tube msg length is too big", *len);
+        (void)fd_set_nonblock(fd);
+        return 0;
+	}
 	*buf = (uint8_t*)malloc(*len);
 	if(!*buf) {
 		log_err("tube read out of memory");