diff --git a/src/testdir/Make_dos.mak b/src/testdir/Make_dos.mak
index 00ceed2..063fd85 100644
--- a/src/testdir/Make_dos.mak
+++ b/src/testdir/Make_dos.mak
@@ -49,6 +49,7 @@
 
 fixff:
 	-$(VIMPROG) -u dos.vim --noplugin "+argdo set ff=dos|upd" +q *.in *.ok
+	-$(VIMPROG) -u dos.vim --noplugin "+argdo set ff=unix|upd" +q dotest.in
 
 clean:
 	-del *.out