diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index 46dc38e..6774a42 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -1,6 +1,6 @@
 /* OpenBSC NAT interface to quagga VTY */
-/* (C) 2010-2012 by Holger Hans Peter Freyther
- * (C) 2010-2012 by On-Waves
+/* (C) 2010-2013 by Holger Hans Peter Freyther
+ * (C) 2010-2013 by On-Waves
  * All Rights Reserved
  *
  * This program is free software; you can redistribute it and/or modify
@@ -554,6 +554,18 @@
 			     &_nat->num_rewr, argv[0]);
 }
 
+DEFUN(cfg_nat_no_number_rewrite,
+      cfg_nat_no_number_rewrite_cmd,
+      "no number-rewrite",
+      NO_STR "Set the file with rewriting rules.\n")
+{
+	talloc_free(_nat->num_rewr_name);
+	_nat->num_rewr_name = NULL;
+
+	bsc_nat_num_rewr_entry_adapt(NULL, &_nat->num_rewr, NULL);
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_nat_smsc_addr,
       cfg_nat_smsc_addr_cmd,
       "rewrite-smsc addr FILENAME",
@@ -1112,6 +1124,7 @@
 
 	/* number rewriting */
 	install_element(NAT_NODE, &cfg_nat_number_rewrite_cmd);
+	install_element(NAT_NODE, &cfg_nat_no_number_rewrite_cmd);
 	install_element(NAT_NODE, &cfg_nat_smsc_addr_cmd);
 	install_element(NAT_NODE, &cfg_nat_smsc_tpdest_cmd);
 	install_element(NAT_NODE, &cfg_nat_sms_clear_tpsrr_cmd);
diff --git a/openbsc/tests/vty_test_runner.py b/openbsc/tests/vty_test_runner.py
index 778cde0..456573d 100644
--- a/openbsc/tests/vty_test_runner.py
+++ b/openbsc/tests/vty_test_runner.py
@@ -96,8 +96,12 @@
     def vty_app(self):
         return (4244, "src/osmo-bsc_nat/osmo-bsc_nat",  "OsmoBSCNAT", "nat")
 
-    def testMoo(self):
-        pass
+    def testRewriteNoRewrite(self):
+        self.vty.enable()
+        res = self.vty.command("configure terminal")
+        res = self.vty.command("nat")
+        res = self.vty.command("number-rewrite rewrite.cfg")
+        res = self.vty.command("no number-rewrite")
 
 
 def add_nat_test(suite, workdir):