1 files changed, 1 insertions, 1 deletions
diff --git a/lib.c b/lib.c
index 103c92cd..59f27aa6 100644
--- a/lib.c
+++ b/lib.c
@@ -215,7 +215,7 @@ val class_check(val cobj, val class_sym)
 {
   type_assert (is_ptr(cobj) && cobj->t.type == COBJ &&
                cobj->co.cls == class_sym,
-               (lit("~a is not of type ~a"), cobj, class_sym, nao));
+               (lit("~s is not of type ~s"), cobj, class_sym, nao));
   return t;
 }