diff --git a/pcl/defs.lisp b/pcl/defs.lisp
index d4ecb609d7b006955c7585dc4754372b2ff964de..565a0cd88deaa8d27280f4bd598afd5720887a43 100644
--- a/pcl/defs.lisp
+++ b/pcl/defs.lisp
@@ -441,7 +441,7 @@
 (defclass kernel:funcallable-instance (function) ()
   (:metaclass built-in-class))
 
-(defclass stream (t) ()
+(defclass stream (kernel:instance) ()
   (:metaclass built-in-class))
 
 (defclass slot-object (t) ()