diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index bb74fad..407e261 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -1061,7 +1061,6 @@
         '\d STORE -1 in $1\_s*' ..
         '\d PUSHS "\["one", "two"\]"\_s*' ..
         '\d BCALL eval(argc 1)\_s*' ..
-        '\d CHECKTYPE list<any> stack\[-1\]\_s*' ..
         '\d FOR $1 -> \d\+\_s*' ..
         '\d STORE $2\_s*' ..
         'res ..= str\_s*' ..
@@ -1071,7 +1070,7 @@
         '\d\+ CONCAT\_s*' ..
         '\d\+ STORE $0\_s*' ..
         'endfor\_s*' ..
-        '\d\+ JUMP -> 6\_s*' ..
+        '\d\+ JUMP -> 5\_s*' ..
         '\d\+ DROP\_s*' ..
         'return res\_s*' ..
         '\d\+ LOAD $0\_s*' ..
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index b9c1c57..1169c86 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -2322,6 +2322,25 @@
     res ..= n .. s
   endfor
   assert_equal('1a2b', res)
+
+  # loop over string
+  res = ''
+  for c in 'aéc̀d'
+    res ..= c .. '-'
+  endfor
+  assert_equal('a-é-c̀-d-', res)
+
+  res = ''
+  for c in ''
+    res ..= c .. '-'
+  endfor
+  assert_equal('', res)
+
+  res = ''
+  for c in test_null_string()
+    res ..= c .. '-'
+  endfor
+  assert_equal('', res)
 enddef
 
 def Test_for_loop_fails()
@@ -2333,10 +2352,17 @@
   CheckDefFailure(['var x = 5', 'for x in range(5)'], 'E1017:')
   CheckScriptFailure(['def Func(arg: any)', 'for arg in range(5)', 'enddef', 'defcompile'], 'E1006:')
   delfunc! g:Func
-  CheckDefFailure(['for i in "text"'], 'E1012:')
   CheckDefFailure(['for i in xxx'], 'E1001:')
   CheckDefFailure(['endfor'], 'E588:')
   CheckDefFailure(['for i in range(3)', 'echo 3'], 'E170:')
+
+  # wrong type detected at compile time
+  CheckDefFailure(['for i in {a: 1}', 'echo 3', 'endfor'], 'E1177: For loop on dict not supported')
+
+  # wrong type detected at runtime
+  g:adict = {a: 1}
+  CheckDefExecFailure(['for i in g:adict', 'echo 3', 'endfor'], 'E1177: For loop on dict not supported')
+  unlet g:adict
 enddef
 
 def Test_for_loop_script_var()
diff --git a/src/testdir/test_vimscript.vim b/src/testdir/test_vimscript.vim
index b57d86d..f12d810 100644
--- a/src/testdir/test_vimscript.vim
+++ b/src/testdir/test_vimscript.vim
@@ -7484,6 +7484,26 @@
   call assert_equal(v:false, eval(string(v:false)))
 endfunction
 
+func Test_for_over_string()
+  let res = ''
+  for c in 'aéc̀d'
+    let res ..= c .. '-'
+  endfor
+  call assert_equal('a-é-c̀-d-', res)
+
+  let res = ''
+  for c in ''
+    let res ..= c .. '-'
+  endfor
+  call assert_equal('', res)
+
+  let res = ''
+  for c in test_null_string()
+    let res ..= c .. '-'
+  endfor
+  call assert_equal('', res)
+endfunc
+
 "-------------------------------------------------------------------------------
 " Modelines								    {{{1
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker