diff --git a/INSTALL b/INSTALL
index 3f6b4ad..06de59a 100644
--- a/INSTALL
+++ b/INSTALL
@@ -14,7 +14,7 @@ Prerequirements
 
 	* xtables(-devel) 1.5.2
 
-	* kernel-source >= 2.6.18 with prepared build/output directory
+	* kernel-source >= 2.6.18.5 with prepared build/output directory
 
 
 Selecting extensions
diff --git a/extensions/compat_xtables.c b/extensions/compat_xtables.c
index cea80e7..05ddb2d 100644
--- a/extensions/compat_xtables.c
+++ b/extensions/compat_xtables.c
@@ -299,7 +299,8 @@ int xtnu_ip_route_me_harder(struct sk_buff *skb, unsigned int addr_type)
 	struct sk_buff *nskb = skb;
 	int ret;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 17)
+	/* Actually this one is valid up to 2.6.18.4, but changed in 2.6.18.5 */
 	ret = ip_route_me_harder(&skb);
 #elif LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 23)
 	ret = ip_route_me_harder(&nskb, addr_type);