diff --git a/examples/nettest/nettest.h b/examples/nettest/nettest.h
index 18e78f222..e1f8537a0 100644
--- a/examples/nettest/nettest.h
+++ b/examples/nettest/nettest.h
@@ -92,9 +92,9 @@
  ****************************************************************************/
 
 #ifdef CONFIG_EXAMPLES_NETTEST_IPv6
-uint16_t g_nettestserver_ipv6[8];
+extern uint16_t g_nettestserver_ipv6[8];
 #else
-uint32_t g_nettestserver_ipv4;
+extern uint32_t g_nettestserver_ipv4;
 #endif
 
 /****************************************************************************