diff --git a/src/testdir/test_spell.vim b/src/testdir/test_spell.vim
index 0fd5ed9..0187a17 100644
--- a/src/testdir/test_spell.vim
+++ b/src/testdir/test_spell.vim
@@ -854,6 +854,21 @@
   bwipe!
 endfunc
 
+func Test_spell_good_word_invalid()
+  " This was adding a word with a 0x02 byte, which causes havoc.
+  enew
+  norm o0
+  sil! norm rzzWs00/
+  2
+  sil! norm VzGprzzW
+  sil! norm z=
+
+  bwipe!
+  " clear the internal word list
+  set enc=latin1
+  set enc=utf-8
+endfunc
+
 func LoadAffAndDic(aff_contents, dic_contents)
   set enc=latin1
   set spellfile=