diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index 3f6e310..c5241fc 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -17,17 +17,15 @@
 #include <linux/sysctl.h>
 
 #ifdef CONFIG_INET
-extern struct ctl_table ipv4_table[];
+#include <net/ip.h>
 #endif
 
-extern struct ctl_table core_table[];
-
 #ifdef CONFIG_NET
-extern struct ctl_table ether_table[];
+#include <linux/if_ether.h>
 #endif
 
 #ifdef CONFIG_TR
-extern struct ctl_table tr_table[];
+#include <linux/if_tr.h>
 #endif
 
 struct ctl_table net_table[] = {