diff --git a/src/slug.c b/src/slug.c
index 55a95be..ab1abbf 100644
--- a/src/slug.c
+++ b/src/slug.c
@@ -77,7 +77,7 @@ r3_slug_t * r3_slug_parse_next(r3_slug_t *s, char **errstr) {
 }
 */
 
-r3_slug_t * r3_slug_parse(const char *needle, int needle_len, char *offset, char **errstr) {
+r3_slug_t * r3_slug_parse(char *needle, int needle_len, char *offset, char **errstr) {
     r3_slug_t * s = r3_slug_new(needle, needle_len);
     if (!s) {
         return NULL;
diff --git a/src/slug.h b/src/slug.h
index bf4763f..4980b1b 100644
--- a/src/slug.h
+++ b/src/slug.h
@@ -43,7 +43,7 @@ r3_slug_t * r3_slug_new(char * path, int path_len);
 
 int r3_slug_check(r3_slug_t *s, char **errstr);
 
-r3_slug_t * r3_slug_parse(const char *needle, int needle_len, char *offset, char **errstr);
+r3_slug_t * r3_slug_parse(char *needle, int needle_len, char *offset, char **errstr);
 
 char * r3_slug_to_str(const r3_slug_t *s);