diff --git a/net/ax25/ax25_addr.c b/net/ax25/ax25_addr.c
index 5f0896a..5524f9c 100644
--- a/net/ax25/ax25_addr.c
+++ b/net/ax25/ax25_addr.c
@@ -39,7 +39,7 @@
 /*
  *	ax25 -> ascii conversion
  */
-char *ax2asc(char *buf, ax25_address *a)
+char *ax2asc(char *buf, const ax25_address *a)
 {
 	char c, *s;
 	int n;
@@ -72,7 +72,7 @@
 /*
  *	ascii -> ax25 conversion
  */
-void asc2ax(ax25_address *addr, char *callsign)
+void asc2ax(ax25_address *addr, const char *callsign)
 {
 	char *s;
 	int n;
@@ -107,7 +107,7 @@
 /*
  *	Compare two ax.25 addresses
  */
-int ax25cmp(ax25_address *a, ax25_address *b)
+int ax25cmp(const ax25_address *a, const ax25_address *b)
 {
 	int ct = 0;
 
@@ -128,7 +128,7 @@
 /*
  *	Compare two AX.25 digipeater paths.
  */
-int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
+int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
 {
 	int i;
 
@@ -149,7 +149,9 @@
  *	Given an AX.25 address pull of to, from, digi list, command/response and the start of data
  *
  */
-unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
+const unsigned char *ax25_addr_parse(const unsigned char *buf, int len,
+	ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags,
+	int *dama)
 {
 	int d = 0;
 
@@ -204,7 +206,8 @@
 /*
  *	Assemble an AX.25 header from the bits
  */
-int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
+int ax25_addr_build(unsigned char *buf, const ax25_address *src,
+	const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
 {
 	int len = 0;
 	int ct  = 0;
@@ -261,7 +264,7 @@
 	return len;
 }
 
-int ax25_addr_size(ax25_digi *dp)
+int ax25_addr_size(const ax25_digi *dp)
 {
 	if (dp == NULL)
 		return 2 * AX25_ADDR_LEN;
@@ -272,7 +275,7 @@
 /*
  *	Reverse Digipeat List. May not pass both parameters as same struct
  */
-void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
+void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
 {
 	int ct;