diff --git a/lib/parser.c b/lib/parser.c
index 7ad2a48..703c8c1 100644
--- a/lib/parser.c
+++ b/lib/parser.c
@@ -22,7 +22,7 @@
  * match extremely simple token=arg style patterns. If the pattern is found,
  * the location(s) of the arguments will be returned in the @args array.
  */
-static int match_one(char *s, char *p, substring_t args[])
+static int match_one(char *s, const char *p, substring_t args[])
 {
 	char *meta;
 	int argc = 0;
@@ -43,7 +43,7 @@
 		p = meta + 1;
 
 		if (isdigit(*p))
-			len = simple_strtoul(p, &p, 10);
+			len = simple_strtoul(p, (char **) &p, 10);
 		else if (*p == '%') {
 			if (*s++ != '%')
 				return 0;
@@ -102,7 +102,7 @@
  */
 int match_token(char *s, match_table_t table, substring_t args[])
 {
-	struct match_token *p;
+	const struct match_token *p;
 
 	for (p = table; !match_one(s, p->pattern, args) ; p++)
 		;
@@ -190,7 +190,7 @@
  * &substring_t @s to the c-style string @to. Caller guarantees that @to is
  * large enough to hold the characters of @s.
  */
-void match_strcpy(char *to, substring_t *s)
+void match_strcpy(char *to, const substring_t *s)
 {
 	memcpy(to, s->from, s->to - s->from);
 	to[s->to - s->from] = '\0';
@@ -204,7 +204,7 @@
  * the &substring_t @s. The caller is responsible for freeing the returned
  * string with kfree().
  */
-char *match_strdup(substring_t *s)
+char *match_strdup(const substring_t *s)
 {
 	char *p = kmalloc(s->to - s->from + 1, GFP_KERNEL);
 	if (p)