diff --git a/src/testdir/test_user_func.vim b/src/testdir/test_user_func.vim
index 6b17534..4721175 100644
--- a/src/testdir/test_user_func.vim
+++ b/src/testdir/test_user_func.vim
@@ -5,6 +5,7 @@
 
 source check.vim
 source shared.vim
+import './vim9.vim' as v9
 
 func Table(title, ...)
   let ret = a:title
@@ -619,7 +620,7 @@
       DeferLevelOne()
   END
   call writefile(lines, 'XdeferQuitall', 'D')
-  let res = system(GetVimCommandClean() .. ' -X -S XdeferQuitall')
+  let res = system(GetVimCommand() .. ' -X -S XdeferQuitall')
   call assert_equal(0, v:shell_error)
   call assert_false(filereadable('XQuitallOne'))
   call assert_false(filereadable('XQuitallTwo'))
@@ -641,7 +642,7 @@
       call Test_defer_in_funcref()
   END
   call writefile(lines, 'XdeferQuitallExpr', 'D')
-  let res = system(GetVimCommandClean() .. ' -X -S XdeferQuitallExpr')
+  let res = system(GetVimCommand() .. ' -X -S XdeferQuitallExpr')
   call assert_equal(0, v:shell_error)
   call assert_false(filereadable('Xentry0'))
   call assert_false(filereadable('Xentry1'))
@@ -695,5 +696,60 @@
   assert_false(filereadable('Xentry2'))
 enddef
 
+func Test_defer_wrong_arguments()
+  call assert_fails('defer delete()', 'E119:')
+  call assert_fails('defer FuncIndex(1)', 'E119:')
+  call assert_fails('defer delete(1, 2, 3)', 'E118:')
+  call assert_fails('defer FuncIndex(1, 2, 3)', 'E118:')
+
+  let lines =<< trim END
+      def DeferFunc0()
+        defer delete()
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E119:')
+  let lines =<< trim END
+      def DeferFunc3()
+        defer delete(1, 2, 3)
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E118:')
+  let lines =<< trim END
+      def DeferFunc2()
+        defer delete(1, 2)
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E1013: Argument 1: type mismatch, expected string but got number')
+
+  def g:FuncOneArg(arg: string)
+    echo arg
+  enddef
+
+  let lines =<< trim END
+      def DeferUserFunc0()
+        defer g:FuncOneArg()
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E119:')
+  let lines =<< trim END
+      def DeferUserFunc2()
+        defer g:FuncOneArg(1, 2)
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E118:')
+  let lines =<< trim END
+      def DeferUserFunc1()
+        defer g:FuncOneArg(1)
+      enddef
+      defcompile
+  END
+  call v9.CheckScriptFailure(lines, 'E1013: Argument 1: type mismatch, expected string but got number')
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab