diff --git a/src/cmp/cmptype.lsp b/src/cmp/cmptype.lsp
index 7dfba46b7..5d6512ef4 100644
--- a/src/cmp/cmptype.lsp
+++ b/src/cmp/cmptype.lsp
@@ -144,9 +144,11 @@
 		 (t
 		  `(AND ,t1 ,t2))))
 	  ((eq tag1 'CONS)
-	   (type-and 'CONS t2))
+	   (cmpwarn "Unsupported CONS type ~S. Replacing it with T." t1)
+	   t2)
 	  ((eq tag2 'CONS)
-	   (type-and t1 'CONS))
+	   (cmpwarn "Unsupported CONS type ~S. Replacing it with T." t2)
+	   t1)
 	  ((null tag1)
 	   (cmpwarn "Unknown type ~S. Assuming it is T." t1)
 	   t2)
@@ -176,15 +178,17 @@
 		 (t
 		  `(OR ,t1 ,t2))))
 	  ((eq tag1 'CONS)
-	   (type-or 'CONS t2))
+	   (cmpwarn "Unsupported CONS type ~S. Replacing it with T." t1)
+	   T)
 	  ((eq tag2 'CONS)
-	   (type-or t1 'CONS))
+	   (cmpwarn "Unsupported CONS type ~S. Replacing it with T." t2)
+	   T)
 	  ((null tag1)
 	   (cmpwarn "Unknown type ~S" t1)
-	   'T)
+	   T)
 	  (t
 	   (cmpwarn "Unknown type ~S" t2)
-	   'T))))
+	   T))))
 
 (defun type>= (type1 type2)
   (subtypep type2 type1))