diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index 78d0a62..7fd8c06 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -258,7 +258,7 @@
         '\d STORE $2\_s*' ..
         '\[x, y; l\] = g:stringlist\_s*' ..
         '\d LOADG g:stringlist\_s*' ..
-        '\d CHECKTYPE list stack\[-1\]\_s*' ..
+        '\d CHECKTYPE list<any> stack\[-1\]\_s*' ..
         '\d CHECKLEN >= 2\_s*' ..
         '\d\+ ITEM 0\_s*' ..
         '\d\+ CHECKTYPE string stack\[-1\]\_s*' ..
@@ -829,7 +829,7 @@
         '\d STORE -1 in $1\_s*' ..
         '\d PUSHS "\["one", "two"\]"\_s*' ..
         '\d BCALL eval(argc 1)\_s*' ..
-        '\d CHECKTYPE list stack\[-1\]\_s*' ..
+        '\d CHECKTYPE list<any> stack\[-1\]\_s*' ..
         '\d FOR $1 -> \d\+\_s*' ..
         '\d STORE $2\_s*' ..
         'res ..= str\_s*' ..
@@ -1144,7 +1144,7 @@
         '\d STORE $0\_s*' ..
         'return res\_s*' ..
         '\d LOAD $0\_s*' ..
-        '\d CHECKTYPE list stack\[-1\]\_s*' ..
+        '\d CHECKTYPE list<number> stack\[-1\]\_s*' ..
         '\d RETURN',
         instr)
   assert_equal([2, 3, 4], AnySlice())
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index b09242e..ff0c75d 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -1438,8 +1438,11 @@
   let old: list<string> = v:oldfiles
   let compl: dict<any> = v:completed_item
 
-  CheckDefFailure(["let old: list<number> = v:oldfiles"], 'E1012: type mismatch, expected list<number> but got list<string>', 1)
-  CheckDefFailure(["let old: dict<number> = v:completed_item"], 'E1012: type mismatch, expected dict<number> but got dict<any>', 1)
+  CheckDefFailure(["let old: list<number> = v:oldfiles"], 'E1012: Type mismatch; expected list<number> but got list<string>', 1)
+  new
+  exec "normal! afoo fo\<C-N>\<Esc>"
+  CheckDefExecFailure(["let old: dict<number> = v:completed_item"], 'E1012: Type mismatch; expected dict<number> but got dict<string>', 1)
+  bwipe!
 enddef
 
 def Test_expr7_special()
@@ -1520,14 +1523,14 @@
 
   CheckDefExecFailure(["echo 1", "let x = [][0]", "echo 3"], 'E684:', 2)
 
-  CheckDefExecFailure(["let x = g:list_mixed['xx']"], 'E1029:', 1)
+  CheckDefExecFailure(["let x = g:list_mixed['xx']"], 'E1012:', 1)
   CheckDefFailure(["let x = g:list_mixed["], 'E1097:', 2)
   CheckDefFailure(["let x = g:list_mixed[0"], 'E1097:', 2)
   CheckDefExecFailure(["let x = g:list_empty[3]"], 'E684:', 1)
-  CheckDefFailure(["let l: list<number> = [234, 'x']"], 'E1012:', 1)
-  CheckDefFailure(["let l: list<number> = ['x', 234]"], 'E1012:', 1)
-  CheckDefFailure(["let l: list<string> = [234, 'x']"], 'E1012:', 1)
-  CheckDefFailure(["let l: list<string> = ['x', 123]"], 'E1012:', 1)
+  CheckDefExecFailure(["let l: list<number> = [234, 'x']"], 'E1012:', 1)
+  CheckDefExecFailure(["let l: list<number> = ['x', 234]"], 'E1012:', 1)
+  CheckDefExecFailure(["let l: list<string> = [234, 'x']"], 'E1012:', 1)
+  CheckDefExecFailure(["let l: list<string> = ['x', 123]"], 'E1012:', 1)
 enddef
 
 def Test_expr7_list_vim9script()
@@ -1731,10 +1734,10 @@
   CheckDefExecFailure(["let x = g:anint.member"], 'E715:', 1)
   CheckDefExecFailure(["let x = g:dict_empty.member"], 'E716:', 1)
 
-  CheckDefFailure(['let x: dict<number> = #{a: 234, b: "1"}'], 'E1012:', 1)
-  CheckDefFailure(['let x: dict<number> = #{a: "x", b: 134}'], 'E1012:', 1)
-  CheckDefFailure(['let x: dict<string> = #{a: 234, b: "1"}'], 'E1012:', 1)
-  CheckDefFailure(['let x: dict<string> = #{a: "x", b: 134}'], 'E1012:', 1)
+  CheckDefExecFailure(['let x: dict<number> = #{a: 234, b: "1"}'], 'E1012:', 1)
+  CheckDefExecFailure(['let x: dict<number> = #{a: "x", b: 134}'], 'E1012:', 1)
+  CheckDefExecFailure(['let x: dict<string> = #{a: 234, b: "1"}'], 'E1012:', 1)
+  CheckDefExecFailure(['let x: dict<string> = #{a: "x", b: 134}'], 'E1012:', 1)
 enddef
 
 def Test_expr7_dict_vim9script()
@@ -1840,7 +1843,7 @@
 
   CheckDefFailure(["let x = g:dict_one.#$!"], 'E1002:', 1)
   CheckDefExecFailure(["let d: dict<any>", "echo d['a']"], 'E716:', 2)
-  CheckDefExecFailure(["let d: dict<number>", "d = g:list_empty"], 'E1029: Expected dict but got list', 2)
+  CheckDefExecFailure(["let d: dict<number>", "d = g:list_empty"], 'E1012: Type mismatch; expected dict<number> but got list<unknown>', 2)
 enddef
 
 def Test_expr7_any_index_slice()
@@ -2311,7 +2314,7 @@
   CheckScriptSuccess(['vim9script'] + lines)
 
   lines = ['let l = [0, 1, 2]', 'echo l[g:astring : g:theone]']
-  CheckDefExecFailure(lines, 'E1029:')
+  CheckDefExecFailure(lines, 'E1012:')
   CheckScriptFailure(['vim9script'] + lines, 'E1030:', 3)
 enddef
 
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index de10724..563e281 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -30,7 +30,7 @@
 def Test_return_something()
   ReturnString()->assert_equal('string')
   ReturnNumber()->assert_equal(123)
-  assert_fails('ReturnGlobal()', 'E1029: Expected number but got string', '', 1, 'ReturnGlobal')
+  assert_fails('ReturnGlobal()', 'E1012: Type mismatch; expected number but got string', '', 1, 'ReturnGlobal')
 enddef
 
 def Test_missing_return()
@@ -487,7 +487,7 @@
     enddef
     let Funcref: func(string) = function('UseNumber')
   END
-  CheckScriptFailure(lines, 'E1012: type mismatch, expected func(string) but got func(number)')
+  CheckScriptFailure(lines, 'E1012: Type mismatch; expected func(string) but got func(number)')
 
   lines =<< trim END
     vim9script
@@ -976,37 +976,37 @@
   let RefVoid: func: void
   RefVoid = FuncNoArgNoRet
   RefVoid = FuncOneArgNoRet
-  CheckDefFailure(['let RefVoid: func: void', 'RefVoid = FuncNoArgRetNumber'], 'E1012: type mismatch, expected func() but got func(): number')
-  CheckDefFailure(['let RefVoid: func: void', 'RefVoid = FuncNoArgRetString'], 'E1012: type mismatch, expected func() but got func(): string')
+  CheckDefFailure(['let RefVoid: func: void', 'RefVoid = FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func(...) but got func(): number')
+  CheckDefFailure(['let RefVoid: func: void', 'RefVoid = FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...) but got func(): string')
 
   let RefAny: func(): any
   RefAny = FuncNoArgRetNumber
   RefAny = FuncNoArgRetString
-  CheckDefFailure(['let RefAny: func(): any', 'RefAny = FuncNoArgNoRet'], 'E1012: type mismatch, expected func(): any but got func()')
-  CheckDefFailure(['let RefAny: func(): any', 'RefAny = FuncOneArgNoRet'], 'E1012: type mismatch, expected func(): any but got func(number)')
+  CheckDefFailure(['let RefAny: func(): any', 'RefAny = FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(): any but got func()')
+  CheckDefFailure(['let RefAny: func(): any', 'RefAny = FuncOneArgNoRet'], 'E1012: Type mismatch; expected func(): any but got func(number)')
 
   let RefNr: func: number
   RefNr = FuncNoArgRetNumber
   RefNr = FuncOneArgRetNumber
-  CheckDefFailure(['let RefNr: func: number', 'RefNr = FuncNoArgNoRet'], 'E1012: type mismatch, expected func(): number but got func()')
-  CheckDefFailure(['let RefNr: func: number', 'RefNr = FuncNoArgRetString'], 'E1012: type mismatch, expected func(): number but got func(): string')
+  CheckDefFailure(['let RefNr: func: number', 'RefNr = FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(...): number but got func()')
+  CheckDefFailure(['let RefNr: func: number', 'RefNr = FuncNoArgRetString'], 'E1012: Type mismatch; expected func(...): number but got func(): string')
 
   let RefStr: func: string
   RefStr = FuncNoArgRetString
   RefStr = FuncOneArgRetString
-  CheckDefFailure(['let RefStr: func: string', 'RefStr = FuncNoArgNoRet'], 'E1012: type mismatch, expected func(): string but got func()')
-  CheckDefFailure(['let RefStr: func: string', 'RefStr = FuncNoArgRetNumber'], 'E1012: type mismatch, expected func(): string but got func(): number')
+  CheckDefFailure(['let RefStr: func: string', 'RefStr = FuncNoArgNoRet'], 'E1012: Type mismatch; expected func(...): string but got func()')
+  CheckDefFailure(['let RefStr: func: string', 'RefStr = FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func(...): string but got func(): number')
 enddef
 
 def Test_func_type_fails()
   CheckDefFailure(['let ref1: func()'], 'E704:')
 
-  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncNoArgRetNumber'], 'E1012: type mismatch, expected func() but got func(): number')
-  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncOneArgNoRet'], 'E1012: type mismatch, expected func() but got func(number)')
-  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncOneArgRetNumber'], 'E1012: type mismatch, expected func() but got func(number): number')
-  CheckDefFailure(['let Ref1: func(bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: type mismatch, expected func(bool) but got func(bool, number)')
-  CheckDefFailure(['let Ref1: func(?bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: type mismatch, expected func(?bool) but got func(bool, number)')
-  CheckDefFailure(['let Ref1: func(...bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: type mismatch, expected func(...bool) but got func(bool, number)')
+  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncNoArgRetNumber'], 'E1012: Type mismatch; expected func() but got func(): number')
+  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncOneArgNoRet'], 'E1012: Type mismatch; expected func() but got func(number)')
+  CheckDefFailure(['let Ref1: func()', 'Ref1 = FuncOneArgRetNumber'], 'E1012: Type mismatch; expected func() but got func(number): number')
+  CheckDefFailure(['let Ref1: func(bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(bool) but got func(bool, number)')
+  CheckDefFailure(['let Ref1: func(?bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(?bool) but got func(bool, number)')
+  CheckDefFailure(['let Ref1: func(...bool)', 'Ref1 = FuncTwoArgNoRet'], 'E1012: Type mismatch; expected func(...bool) but got func(bool, number)')
 
   CheckDefFailure(['let RefWrong: func(string ,number)'], 'E1068:')
   CheckDefFailure(['let RefWrong: func(string,number)'], 'E1069:')
@@ -1026,7 +1026,7 @@
   str = FuncOneArgRetAny('yes')
   str->assert_equal('yes')
 
-  CheckDefFailure(['let str: string', 'str = FuncNoArgRetNumber()'], 'E1012: type mismatch, expected string but got number')
+  CheckDefFailure(['let str: string', 'str = FuncNoArgRetNumber()'], 'E1012: Type mismatch; expected string but got number')
 enddef
 
 def MultiLine(
@@ -1204,7 +1204,7 @@
   return join(Ref(), ' ')
 enddef
 
-def ExtendRef(Ref: func(string), add: string)
+def ExtendRef(Ref: func(string): list<string>, add: string)
   Ref(add)
 enddef
 
@@ -1408,7 +1408,7 @@
 enddef
 
 def Test_wrong_dict_key_type()
-  assert_fails('Wrong_dict_key_type([1, 2, 3])', 'E1029:')
+  assert_fails('Wrong_dict_key_type([1, 2, 3])', 'E1012:')
 enddef
 
 def Line_continuation_in_def(dir: string = ''): string
@@ -1422,7 +1422,7 @@
   Line_continuation_in_def('.')->assert_equal('full')
 enddef
 
-def Line_continuation_in_lambda(): list<number>
+def Line_continuation_in_lambda(): list<string>
   let x = range(97, 100)
       ->map({_, v -> nr2char(v)
           ->toupper()})
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index 936c7dd..bb2bfaf 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -180,9 +180,9 @@
   CheckDefFailure(['&notex += 3'], 'E113:')
   CheckDefFailure(['&ts ..= "xxx"'], 'E1019:')
   CheckDefFailure(['&ts = [7]'], 'E1012:')
-  CheckDefExecFailure(['&ts = g:alist'], 'E1029: Expected number but got list')
+  CheckDefExecFailure(['&ts = g:alist'], 'E1012: Type mismatch; expected number but got list<number>')
   CheckDefFailure(['&ts = "xx"'], 'E1012:')
-  CheckDefExecFailure(['&ts = g:astring'], 'E1029: Expected number but got string')
+  CheckDefExecFailure(['&ts = g:astring'], 'E1012: Type mismatch; expected number but got string')
   CheckDefFailure(['&path += 3'], 'E1012:')
   CheckDefExecFailure(['&bs = "asdf"'], 'E474:')
   # test freeing ISN_STOREOPT
@@ -958,14 +958,14 @@
   try
     # string slice returns a string, not a number
     n = g:astring[3]
-  catch /E1029:/
+  catch /E1012:/
     n = 77
   endtry
   assert_equal(77, n)
 
   try
     n = l[g:astring]
-  catch /E1029:/
+  catch /E1012:/
     n = 88
   endtry
   assert_equal(88, n)
@@ -1016,7 +1016,7 @@
   let nd: dict<any>
   try
     nd = {g:anumber: 1}
-  catch /E1029:/
+  catch /E1012:/
     n = 266
   endtry
   assert_equal(266, n)
@@ -1030,7 +1030,7 @@
 
   try
     &ts = g:astring
-  catch /E1029:/
+  catch /E1012:/
     n = 288
   endtry
   assert_equal(288, n)
@@ -3184,6 +3184,24 @@
   CheckScriptSuccess(lines)
 enddef
 
+let g:dict_number = #{one: 1, two: 2}
+
+def Test_let_list_dict_type()
+  let ll: list<number>
+  ll = [1, 2, 2, 3, 3, 3]->uniq()
+  ll->assert_equal([1, 2, 3])
+
+  let dd: dict<number>
+  dd = g:dict_number
+  dd->assert_equal(g:dict_number)
+
+  let lines =<< trim END
+      let ll: list<number>
+      ll = [1, 2, 3]->map('"one"')
+  END
+  CheckDefExecFailure(lines, 'E1012: Type mismatch; expected list<number> but got list<string>')
+enddef
+
 def Test_forward_declaration()
   let lines =<< trim END
     vim9script