diff --git a/sys/amd64/amd64/in_cksum.c b/sys/amd64/amd64/in_cksum.c
index 4b7fca2055ee..068134aa59ad 100644
--- a/sys/amd64/amd64/in_cksum.c
+++ b/sys/amd64/amd64/in_cksum.c
@@ -88,14 +88,10 @@ union q_util {
 	u_int64_t q;
 };
 
-u_int64_t	in_cksumdata __P((caddr_t buf, int len));
-
-u_int64_t
-in_cksumdata(buf, len)
-	register caddr_t buf;
-	register int len;
+static u_int64_t
+in_cksumdata(const void *buf, size_t len)
 {
-	const u_int32_t *lw = (u_int32_t *) buf;
+	const u_int32_t *lw = (const u_int32_t *) buf;
 	u_int64_t sum = 0;
 	u_int64_t prefilled;
 	int offset;
@@ -195,10 +191,7 @@ in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c)
 }
 
 u_short
-in_cksum_skip(m, len, skip)
-	struct mbuf *m;
-	int len;
-	int skip;
+in_cksum_skip(struct mbuf *m, int len, int skip)
 {
 	u_int64_t sum = 0;
 	int mlen = 0;
@@ -238,10 +231,9 @@ in_cksum_skip(m, len, skip)
 	return (~sum & 0xffff);
 }
 
-u_int in_cksum_hdr(ip)
-    const struct ip *ip;
+u_int in_cksum_hdr(const struct ip *ip)
 {
-    u_int64_t sum = in_cksumdata((caddr_t) ip, sizeof(struct ip));
+    u_int64_t sum = in_cksumdata(ip, sizeof(struct ip));
     union q_util q_util;
     union l_util l_util;
     REDUCE16;
diff --git a/sys/ia64/ia64/in_cksum.c b/sys/ia64/ia64/in_cksum.c
index 4b7fca2055ee..068134aa59ad 100644
--- a/sys/ia64/ia64/in_cksum.c
+++ b/sys/ia64/ia64/in_cksum.c
@@ -88,14 +88,10 @@ union q_util {
 	u_int64_t q;
 };
 
-u_int64_t	in_cksumdata __P((caddr_t buf, int len));
-
-u_int64_t
-in_cksumdata(buf, len)
-	register caddr_t buf;
-	register int len;
+static u_int64_t
+in_cksumdata(const void *buf, size_t len)
 {
-	const u_int32_t *lw = (u_int32_t *) buf;
+	const u_int32_t *lw = (const u_int32_t *) buf;
 	u_int64_t sum = 0;
 	u_int64_t prefilled;
 	int offset;
@@ -195,10 +191,7 @@ in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c)
 }
 
 u_short
-in_cksum_skip(m, len, skip)
-	struct mbuf *m;
-	int len;
-	int skip;
+in_cksum_skip(struct mbuf *m, int len, int skip)
 {
 	u_int64_t sum = 0;
 	int mlen = 0;
@@ -238,10 +231,9 @@ in_cksum_skip(m, len, skip)
 	return (~sum & 0xffff);
 }
 
-u_int in_cksum_hdr(ip)
-    const struct ip *ip;
+u_int in_cksum_hdr(const struct ip *ip)
 {
-    u_int64_t sum = in_cksumdata((caddr_t) ip, sizeof(struct ip));
+    u_int64_t sum = in_cksumdata(ip, sizeof(struct ip));
     union q_util q_util;
     union l_util l_util;
     REDUCE16;