1 files changed, 1 insertions, 1 deletions
diff --git a/ruby.c b/ruby.c
index 3188b7135b..2afedf9a0d 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1803,7 +1803,7 @@ ruby_prog_init(void)
     rb_define_hooked_variable("$VERBOSE", &ruby_verbose, 0, verbose_setter);
     rb_define_hooked_variable("$-v", &ruby_verbose, 0, verbose_setter);
     rb_define_hooked_variable("$-w", &ruby_verbose, 0, verbose_setter);
-    rb_define_hooked_variable("$-W", &ruby_verbose, opt_W_getter, 0);
+    rb_define_hooked_variable("$-W", &ruby_verbose, opt_W_getter, rb_gvar_readonly_setter);
     rb_define_variable("$DEBUG", &ruby_debug);
     rb_define_variable("$-d", &ruby_debug);