diff --git a/src/testdir/test_filter_map.vim b/src/testdir/test_filter_map.vim
index ab7e196..1767a99 100644
--- a/src/testdir/test_filter_map.vim
+++ b/src/testdir/test_filter_map.vim
@@ -182,6 +182,7 @@
     call assert_equal('', map('abc', LSTART i, x LMIDDLE '' LEND))
     call assert_equal('', map('', "v:val == 'a'"))
     call assert_equal('', map(test_null_string(), "v:val == 'a'"))
+    call assert_fails('echo map("abc", "10")', 'E928:')
   END
   call CheckLegacyAndVim9Success(lines)
 
diff --git a/src/testdir/test_listdict.vim b/src/testdir/test_listdict.vim
index 2fea643..e7b6588 100644
--- a/src/testdir/test_listdict.vim
+++ b/src/testdir/test_listdict.vim
@@ -783,6 +783,32 @@
   call CheckScriptFailure(lines, 'E741:')
 endfunc
 
+" Lock one item in a list
+func Test_list_item_lock_map()
+  let lines =<< trim END
+      VAR l = [99, 100, 101]
+      lockvar l[1]
+      call assert_fails("echo map(l, 'v:val + 200')", 'E741:')
+      call assert_equal([299, 100, 101], l)
+  END
+  " This won't work in a :def function
+  call CheckTransLegacySuccess(lines)
+  call CheckTransVim9Success(lines)
+endfunc
+
+" Lock one item in a dict
+func Test_dict_item_lock_map()
+  let lines =<< trim END
+      VAR d = {'a': 99, 'b': 100, 'c': 101}
+      lockvar d.b
+      call assert_fails("echo map(d, 'v:val + 200')", 'E741:')
+      call assert_equal({'a': 299, 'b': 100, 'c': 101}, d)
+  END
+  " This won't work in a :def function
+  call CheckTransLegacySuccess(lines)
+  call CheckTransVim9Success(lines)
+endfunc
+
 " No extend() after lock on dict item
 func Test_dict_lock_extend()
   let d = {'a': 99, 'b': 100}
diff --git a/src/testdir/test_sort.vim b/src/testdir/test_sort.vim
index 82f70ff..783ca9e 100644
--- a/src/testdir/test_sort.vim
+++ b/src/testdir/test_sort.vim
@@ -1548,4 +1548,20 @@
   close!
 endfunc
 
+" Test for sort() using a dict function
+func Test_sort_using_dict_func()
+  func DictSort(a, b) dict
+    if self.order == 'reverse'
+      return a:b - a:a
+    else
+      return a:a - a:b
+    endif
+  endfunc
+  let d = #{order: ''}
+  call assert_equal([1, 2, 3], sort([2, 1, 3], 'DictSort', d))
+  let d = #{order: 'reverse'}
+  call assert_equal([3, 2, 1], sort([2, 1, 3], 'DictSort', d))
+  delfunc DictSort
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab