Bug: https://bugs.gentoo.org/898860
--- a/tools/src/qsfilter2.c
+++ b/tools/src/qsfilter2.c
@@ -1800,7 +1800,7 @@ int main(int argc, const char * const argv[]) {
   printf("# --------------------------------------------------------\n");
 
   {
-    STACK_OF(qs_rule_t) *st = sk_new(STACK_qs_cmp);
+    STACK_OF(qs_rule_t) *st = sk_new((qs_rule_t *)STACK_qs_cmp);
     qs_rule_t *r;
     int j = 1;
     entry = (apr_table_entry_t *)apr_table_elts(rules)->elts;