src/class-output.lisp: Leave `*instance-class*' unbound at top-level.

diff --git a/src/class-output.lisp b/src/class-output.lisp
index ef823558ee0f53f913179d6f1e302beea110b331..45a49097b43a3a26c82d46b18af4af01354ccc24 100644 (file)
--- a/src/class-output.lisp
+++ b/src/class-output.lisp
@@ -542,7 +542,7 @@ (defmethod hook-output ((choff chain-offset) (reason (eql :h)) sequencer)
 ;;; Implementation output.
 
 (export '*instance-class*)
-(defvar *instance-class* nil
+(defvar-unbound *instance-class*
   "The class currently being output.
 
    This is bound during the `hook-output' traversal of a class layout for