1 files changed, 1 insertions, 1 deletions
diff --git a/ruby.c b/ruby.c
index ad3c172971..86230735c7 100644
--- a/ruby.c
+++ b/ruby.c
@@ -821,7 +821,7 @@ proc_options(int argc, char **argv)
 		}
 		if (!*s)
 		    break;
-		if (!strchr("IdvwrK", *s))
+		if (!strchr("IdvwWrK", *s))
 		    rb_raise(rb_eRuntimeError,
 			     "illegal switch in RUBYOPT: -%c", *s);
 		s = moreswitches(s);