1 files changed, 1 insertions, 1 deletions
diff --git a/prec.c b/prec.c
index 60d9c693eb..8f28648715 100644
--- a/prec.c
+++ b/prec.c
@@ -46,7 +46,7 @@ prec_induced_from(module, x)
     VALUE module, x;
 {
     rb_raise(rb_eTypeError, "undefined conversion from %s into %s",
-            rb_class2name(CLASS_OF(x)), rb_class2name(module));
+            rb_obj_classname(x), rb_class2name(module));
     return Qnil;		/* not reached */
 }