diff --git a/extensions/xt_psd.c b/extensions/xt_psd.c
index 63ba586..04d1453 100644
--- a/extensions/xt_psd.c
+++ b/extensions/xt_psd.c
@@ -105,8 +105,10 @@ xt_psd_match(const struct sk_buff *pskb, struct xt_action_param *match)
 	const struct iphdr *iph;
 	const struct tcphdr *tcph;
 	const struct udphdr *udph;
-	struct tcphdr _tcph;
-	struct udphdr _udph;
+	union {
+		struct tcphdr tcph;
+		struct udphdr udph;
+	} _buf;
 	struct in_addr addr;
 	u_int16_t src_port,dest_port;
   	u_int8_t tcp_flags, proto;
@@ -139,7 +141,7 @@ xt_psd_match(const struct sk_buff *pskb, struct xt_action_param *match)
 
 	if (proto == IPPROTO_TCP) {
 		tcph = skb_header_pointer(pskb, match->thoff,
-		       sizeof(_tcph), &_tcph);
+		       sizeof(_buf.tcph), &_buf.tcph);
 		if (tcph == NULL)
 			return false;
 
@@ -149,7 +151,7 @@ xt_psd_match(const struct sk_buff *pskb, struct xt_action_param *match)
 		tcp_flags = *((u_int8_t*)tcph + 13);
 	} else if (proto == IPPROTO_UDP || proto == IPPROTO_UDPLITE) {
 		udph = skb_header_pointer(pskb, match->thoff,
-		       sizeof(_udph), &_udph);
+		       sizeof(_buf.udph), &_buf.udph);
 		if (udph == NULL)
 			return false;
 		src_port  = udph->source;