--- sbcl/src/compiler/array-tran.lisp	2013-03-16 16:50:26.276623280 -0700
+++ sbclpatch.lisp	2013-03-16 16:56:11.998337621 -0700
@@ -627,8 +627,9 @@
                  (spec `(simple-array
                          ,(cond ((null element-type) t)
                                 ((and (constant-lvar-p element-type)
-                                      (ir1-transform-specifier-type
-                                       (lvar-value element-type)))
+                                      (not (unknown-type-p
+					    (ir1-transform-specifier-type
+					     (lvar-value element-type)))))
                                  (sb!xc:upgraded-array-element-type
                                   (lvar-value element-type)))
                                 (t '*))