diff --git a/sys/arch/sun3/include/vmparam.h b/sys/arch/sun3/include/vmparam.h
index 86ed29ce7406..ca3ccc5af68f 100644
--- a/sys/arch/sun3/include/vmparam.h
+++ b/sys/arch/sun3/include/vmparam.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: vmparam.h,v 1.22 1999/04/05 14:35:13 gwr Exp $	*/
+/*	$NetBSD: vmparam.h,v 1.23 1999/04/10 02:15:46 gwr Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -39,6 +39,10 @@
 #ifdef	_SUN3X_
 #include <machine/vmparam3x.h>
 #endif	/* SUN3X */
+#ifdef	_LKM
+#define	USRSTACK KERNBASE
+extern	char KERNBASE[];
+#endif	/* _LKM */
 
 /* This is needed by some LKMs. */
 #define VM_PHYSSEG_MAX		4