diff --git a/net.c b/net.c
index 76e44c9c98..f2b472d5c6 100644
--- a/net.c
+++ b/net.c
@@ -2443,6 +2443,7 @@ int net_client_init(Monitor *mon, const char *device, const char *p)
             goto out;
         }
         nd = &nd_table[idx];
+        memset(nd, 0, sizeof(*nd));
         macaddr = nd->macaddr;
         macaddr[0] = 0x52;
         macaddr[1] = 0x54;
@@ -2818,7 +2819,7 @@ void net_client_uninit(NICInfo *nd)
     qemu_free(nd->devaddr);
     qemu_free(nd->id);
 
-    memset(nd, 0, sizeof(*nd));
+    nd->used = 0;
 }
 
 static int net_host_check_device(const char *device)