diff --git a/tools/Makefile b/tools/Makefile
index 0cd0eb296882..50d2b51623e6 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.101 2006/07/17 11:02:02 tron Exp $
+#	$NetBSD: Makefile,v 1.102 2006/07/17 13:54:46 tron Exp $
 
 .include <bsd.own.mk>
 
@@ -118,10 +118,12 @@ all-${dir} depend-${dir} dependall-${dir} install-${dir}:
 .include <bsd.subdir.mk>
 .include <bsd.obj.mk>
 
-.if exists(PREVIOUSTOOLDIR)
+.if !defined(PREVIOUSTOOLDIR)
+.  if exists(PREVIOUSTOOLDIR)
 PREVIOUSTOOLDIR!=	cat PREVIOUSTOOLDIR
-.else
+.  else
 PREVIOUSTOOLDIR=	
+.  endif
 .endif
 
 CLEANFILES+=	PREVIOUSTOOLDIR
@@ -133,9 +135,9 @@ realall realdepend: .MAKE
 	@echo "***     !=  TOOLDIR '${TOOLDIR}'"
 	@echo "*** Cleaning mis-matched tools"
 	rm -f PREVIOUSTOOLDIR
-	(cd ${.CURDIR} && ${MAKE} cleandir)
+	(cd ${.CURDIR} && ${MAKE} PREVIOUSTOOLDIR=${PREVIOUSTOOLDIR} cleandir)
 .endif
-	echo ${TOOLDIR} > PREVIOUSTOOLDIR
+	echo ${TOOLDIR} >PREVIOUSTOOLDIR
 
 # For each .WAIT point, make sure the immediately preceding target is
 # installed before building anything after that point.