--- a/vl.c
+++ b/vl.c
@@ -1700,7 +1700,7 @@ static int serial_parse(const char *devname)
          fprintf(stderr, "qemu: too many serial ports\n");
          exit(1);
      }
-    snprintf(label, sizeof(label), "serial%d", index);
+    snprintf(label, sizeof(label), "serial %d", index);
      serial_hds[index] = qemu_chr_open(label, devname, NULL);
      if (!serial_hds[index]) {
          fprintf(stderr, "qemu: could not open serial device '%s': %s\n",