Fix some pedantic warnings

1 files changed, 1 insertions, 1 deletions

diff --git a/src/sp_utils.h b/src/sp_utils.h
index 61a4c53..5b22e8a 100644
--- a/src/sp_utils.h
+++ b/src/sp_utils.h
@@ -58,7 +58,7 @@ void sp_log_disable(const char *restrict, const char *restrict,
                     const char *restrict, const sp_disabled_function *);
 void sp_log_disable_ret(const char *restrict, const char *restrict,
                         const sp_disabled_function *);
-char *sp_getenv(char *);
+char *sp_getenv(const char *);
 int is_regexp_matching(const pcre *, const char *);
 int hook_function(const char *, HashTable *,
                   void (*)(INTERNAL_FUNCTION_PARAMETERS), bool);