diff --git a/src/testdir/test_retab.vim b/src/testdir/test_retab.vim
index c7190aa..6133e8f 100644
--- a/src/testdir/test_retab.vim
+++ b/src/testdir/test_retab.vim
@@ -70,6 +70,8 @@
   call assert_equal("    a       b        c    ",         Retab('!', 3))
   call assert_equal("    a       b        c    ",         Retab('',  5))
   call assert_equal("    a       b        c    ",         Retab('!', 5))
+
+  set tabstop& expandtab&
 endfunc
 
 func Test_retab_error()
@@ -80,4 +82,21 @@
   call assert_fails('ret 80000000000000000000', 'E475:')
 endfunc
 
+func Test_retab_endless()
+  new
+  call setline(1, "\t0\t")
+  let caught = 'no'
+  try
+    while 1
+      set ts=4000
+      retab 4
+    endwhile
+  catch /E1240/
+    let caught = 'yes'
+  endtry
+  bwipe!
+  set tabstop&
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab