diff --git a/compiler/debug-dump.lisp b/compiler/debug-dump.lisp
index 32b5d81b7e558767ac0d0c0955f520e5b5eb1438..da2a180eca0e62bcb97afccb239b8bd0885696bf 100644
--- a/compiler/debug-dump.lisp
+++ b/compiler/debug-dump.lisp
@@ -263,7 +263,7 @@
 	      (frob)))))
     
     (if max
-	(coerce seq `(vector (integer 0 ,max)))
+	(coerce seq `(simple-array (integer 0 ,max)))
 	(coerce seq 'simple-vector))))