--- a/src/session-child.c
+++ b/src/session-child.c
@@ -193,8 +193,8 @@
 }
 
 /* GNU provides this but we can't rely on that so let's make our own version */
-static void
-updwtmpx (const gchar *wtmp_file, struct utmpx *ut)
+void
+updwtmpx (const char *wtmp_file, const struct utmpx *ut)
 {
     struct utmp u;
     memset (&u, 0, sizeof (u));