diff --git a/main.c b/main.c
index f96985d..e0083b8 100644
--- a/main.c
+++ b/main.c
@@ -12,7 +12,7 @@ static VALUE eval(const char * string)
 //        fprintf(stderr, "rb_eval_string_protect() returned state %d!\n", state);
         VALUE e = rb_errinfo();
         VALUE s = rb_funcall(e, rb_intern("message"), 0);
-        printf("%s\n", StringValueCStr(s));
+        fprintf(stderr, "%s\n", StringValueCStr(s));
         rb_set_errinfo(Qnil);
     }
     return v;