Index: /trunk/source/compiler/nx2.lisp
===================================================================
--- /trunk/source/compiler/nx2.lisp	(revision 14977)
+++ /trunk/source/compiler/nx2.lisp	(revision 14978)
@@ -387,5 +387,7 @@
                                                    (- const-amt)))
                    (progn
-                     (backend-use-operator (%nx1-operator require-fixnum)
+                     (backend-use-operator (target-word-size-case
+                                            (32 (%nx1-operator require-u32))
+                                            (64 (%nx1-operator require-u64)))
                                            seg
                                            nil