diff --git a/src/testdir/test_swap.vim b/src/testdir/test_swap.vim
index 7532655..4ba7bb6 100644
--- a/src/testdir/test_swap.vim
+++ b/src/testdir/test_swap.vim
@@ -420,7 +420,7 @@
   if has('job')
     " Execute 'echo' as a temporary job, and return its pid as an unused pid.
     if has('win32')
-      let cmd = 'cmd /c echo'
+      let cmd = 'cmd /D /c echo'
     else
       let cmd = 'echo'
     endif