diff --git a/src/testdir/test_visual.vim b/src/testdir/test_visual.vim
index 295e16f..f152e7b 100644
--- a/src/testdir/test_visual.vim
+++ b/src/testdir/test_visual.vim
@@ -1534,4 +1534,25 @@
   exe 'bwipe!' buf2
 endfunc
 
+" Check fix for the heap-based buffer overflow bug found in the function
+" utfc_ptr2len and reported at
+" https://huntr.dev/bounties/ae933869-a1ec-402a-bbea-d51764c6618e
+func Test_heap_buffer_overflow()
+  enew
+  set updatecount=0
+
+  norm R0
+  split other
+  norm R000
+  exe "norm \<C-V>l"
+  ball
+  call assert_equal(getpos("."), getpos("v"))
+  call assert_equal('n', mode())
+  norm zW
+
+  %bwipe!
+  set updatecount&
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab