Index: /trunk/source/lisp-kernel/x86-exceptions.c
===================================================================
--- /trunk/source/lisp-kernel/x86-exceptions.c	(revision 12826)
+++ /trunk/source/lisp-kernel/x86-exceptions.c	(revision 12827)
@@ -836,5 +836,5 @@
 
 	  /* The magic 2 means this was a write to a watchd object */
-	  skip = callback_to_lisp(tcr, cmain, xp, xcf, SIGSEGV, 2, addr, obj);
+	  skip = callback_to_lisp(tcr, cmain, xp, xcf, SIGSEGV, 2, (natural) addr, obj);
 	  xpPC(xp) += skip;
 	  return true;