diff --git a/src/testdir/test_writefile.vim b/src/testdir/test_writefile.vim
index db17e6f..98a06eb 100644
--- a/src/testdir/test_writefile.vim
+++ b/src/testdir/test_writefile.vim
@@ -1,5 +1,7 @@
 " Tests for the writefile() function and some :write commands.
 
+source check.vim
+
 func Test_writefile()
   let f = tempname()
   call writefile(["over","written"], f, "b")
@@ -183,9 +185,7 @@
 " Test for ':w !<cmd>' to pipe lines from the current buffer to an external
 " command.
 func Test_write_pipe_to_cmd()
-  if !has('unix')
-    return
-  endif
+  CheckUnix
   new
   call setline(1, ['L1', 'L2', 'L3', 'L4'])
   2,3w !cat > Xfile