--- a/src/testdir/Make_dos.mak
+++ b/src/testdir/Make_dos.mak
@@ -19,7 +19,7 @@ SCRIPTS16 =	test1.out test19.out test20.
 		test44.out test45.out test46.out test47.out \
 		test48.out test51.out test53.out test54.out \
 		test55.out test56.out test57.out test58.out test59.out \
-		test60.out test61.out test62.out test63.out
+		test60.out test61.out test62.out test63.out test64.out
 
 SCRIPTS =	test3.out test4.out test5.out test6.out test7.out \
 		test8.out test9.out test11.out test13.out test14.out \
@@ -51,19 +51,19 @@ fixff:
 
 clean:
 	-del *.out
-	-del test.ok
-	-del small.vim
-	-del tiny.vim
-	-del mbyte.vim
+	-if exist test.ok del test.ok
+	-if exist small.vim del small.vim
+	-if exist tiny.vim del tiny.vim
+	-if exist mbyte.vim del mbyte.vim
 	-del X*
-	-del viminfo
+	-if exist viminfo del viminfo
 
 .in.out:
 	copy $*.ok test.ok
 	$(VIMPROG) -u dos.vim -U NONE --noplugin -s dotest.in $*.in
 	diff test.out $*.ok
-	-del $*.out
+	-if exist $*.out del $*.out
 	rename test.out $*.out
 	-del X*
 	-del test.ok
-	-del viminfo
+	-if exist viminfo del viminfo