diff --git a/src/testdir/test_expand.vim b/src/testdir/test_expand.vim
index ce414e4..638f9c7 100644
--- a/src/testdir/test_expand.vim
+++ b/src/testdir/test_expand.vim
@@ -90,14 +90,26 @@
   " Test for expression expansion `=
   let $FOO= "blue"
   call assert_equal("blue sky", expandcmd("`=$FOO .. ' sky'`"))
+  let x = expandcmd("`=axbycz`")
+  call assert_equal('`=axbycz`', x)
+  call assert_fails('let x = expandcmd("`=axbycz`", #{errmsg: 1})', 'E121:')
+  let x = expandcmd("`=axbycz`", #{abc: []})
+  call assert_equal('`=axbycz`', x)
 
   " Test for env variable with spaces
   let $FOO= "foo bar baz"
   call assert_equal("e foo bar baz", expandcmd("e $FOO"))
 
-  if has('unix')
-    " test for using the shell to expand a command argument
-    call assert_equal('{1..4}', expandcmd('{1..4}'))
+  if has('unix') && executable('bash')
+    " test for using the shell to expand a command argument.
+    " only bash supports the {..} syntax
+    set shell=bash
+    let x = expandcmd('{1..4}')
+    call assert_equal('{1..4}', x)
+    call assert_fails("let x = expandcmd('{1..4}', #{errmsg: v:true})", 'E77:')
+    let x = expandcmd('{1..4}', #{error: v:true})
+    call assert_equal('{1..4}', x)
+    set shell&
   endif
 
   unlet $FOO
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 01f29d9..b20ff14 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -1020,6 +1020,7 @@
   expandcmd('')->assert_equal('')
 
   v9.CheckDefAndScriptFailure(['expandcmd([1])'], ['E1013: Argument 1: type mismatch, expected string but got list<number>', 'E1174: String required for argument 1'])
+  v9.CheckDefAndScriptFailure(['expandcmd("abc", [])'], ['E1013: Argument 2: type mismatch, expected dict<any> but got list<unknown>', 'E1206: Dictionary required for argument 2'])
 enddef
 
 def Test_extend_arg_types()