1 files changed, 2 insertions, 1 deletions
diff --git a/lib.c b/lib.c
index fbc44315..64dfb7d0 100644
--- a/lib.c
+++ b/lib.c
@@ -183,7 +183,8 @@ val type_check3(val obj, int t1, int t2, int t3)
 
 val class_check(val cobj, val class_sym)
 {
-  type_assert (cobj && cobj->t.type == COBJ && cobj->co.cls == 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));
   return t;
 }