diff --git a/compiler/vop.lisp b/compiler/vop.lisp
index c91b9fc25dc162f1b7ff7395664b69456ee7e2ec..18e6b0952f78b56b36328305103e884a8e41064c 100644
--- a/compiler/vop.lisp
+++ b/compiler/vop.lisp
@@ -954,10 +954,9 @@
   ;;
   ;; True if this SC or one of its alternates in in the NUMBER-STACK SB.
   (number-stack-p nil :type boolean)
-
   ;;
   ;; Alignment restriction.  The offset must be an even multiple of this.
-  (alignment 1 :type (integer 1)))
+  (alignment 1 :type (and index (integer 1))))
 
 (defprinter sc
   name)