diff --git a/src/testdir/test_cmdwin.vim b/src/testdir/test_cmdwin.vim
index 6a420ed..dc68894 100644
--- a/src/testdir/test_cmdwin.vim
+++ b/src/testdir/test_cmdwin.vim
@@ -404,5 +404,27 @@
   bwipe!
 endfunc
 
+" This was resulting in a window with negative width.
+" The test doesn't reproduce the illegal memory access though...
+func Test_cmdwin_split_often()
+  let lines = &lines
+  let columns = &columns
+  set t_WS=
+
+  try
+    set encoding=iso8859
+    set ruler
+    winsize 0 0
+    noremap 0 H
+    sil norm 0000000q:
+  catch /E36:/
+  endtry
+
+  bwipe!
+  set encoding=utf8
+  let &lines = lines
+  let &columns = columns
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab