1 files changed, 1 insertions, 1 deletions

diff --git a/src/sp_utils.h b/src/sp_utils.h
index 97c97fd..c094fac 100644
--- a/src/sp_utils.h
+++ b/src/sp_utils.h
@@ -46,7 +46,7 @@
 
 void sp_log_msg(char const *feature, int type, const char *fmt, ...);
 int compute_hash(const char *const filename, char *file_hash);
-const zend_string *sp_zval_to_zend_string(zval *);
+const zend_string *sp_zval_to_zend_string(const zval *);
 bool sp_match_value(const zend_string *, const zend_string *, const sp_pcre *);
 bool sp_match_array_key(const zval *, const zend_string *, const sp_pcre *);
 bool sp_match_array_value(const zval *, const zend_string *, const sp_pcre *);