: disable-optimizer ( -- )
f compiler-impl set-global ;
-{ "prettyprint" "compiler" } "compiler.prettyprint" require-when
-{ "threads" "compiler" } "compiler.threads" require-when
+USE-WHEN-LOADED: compiler.prettyprint { "prettyprint" "compiler" }
+USE-WHEN-LOADED: compiler.threads { "threads" "compiler" }