diff --git a/src/list.c b/src/list.c
index 0bca0b5..d6357f7 100644
--- a/src/list.c
+++ b/src/list.c
@@ -1985,10 +1985,18 @@
 						    : N_("filter() argument"));
     int		save_did_emsg;
     int		idx = 0;
+    type_T	*type = NULL;
+    garray_T	type_list;
 
     // map() and filter() return the first argument, also on failure.
     if (filtermap != FILTERMAP_MAPNEW)
 	copy_tv(&argvars[0], rettv);
+    if (filtermap == FILTERMAP_MAP && in_vim9script())
+    {
+	// Check that map() does not change the type of the dict.
+	ga_init2(&type_list, sizeof(type_T *), 10);
+	type = typval2type(argvars, &type_list);
+    }
 
     if (argvars[0].v_type == VAR_BLOB)
     {
@@ -1998,7 +2006,7 @@
 	    rettv->vval.v_blob = NULL;
 	}
 	if ((b = argvars[0].vval.v_blob) == NULL)
-	    return;
+	    goto theend;
     }
     else if (argvars[0].v_type == VAR_LIST)
     {
@@ -2010,7 +2018,7 @@
 	if ((l = argvars[0].vval.v_list) == NULL
 	      || (filtermap == FILTERMAP_FILTER
 			    && value_check_lock(l->lv_lock, arg_errmsg, TRUE)))
-	    return;
+	    goto theend;
     }
     else if (argvars[0].v_type == VAR_DICT)
     {
@@ -2022,12 +2030,12 @@
 	if ((d = argvars[0].vval.v_dict) == NULL
 	      || (filtermap == FILTERMAP_FILTER
 			    && value_check_lock(d->dv_lock, arg_errmsg, TRUE)))
-	    return;
+	    goto theend;
     }
     else
     {
 	semsg(_(e_listdictblobarg), ermsg);
-	return;
+	goto theend;
     }
 
     expr = &argvars[1];
@@ -2055,7 +2063,7 @@
 	    if (filtermap == FILTERMAP_MAPNEW)
 	    {
 		if (rettv_dict_alloc(rettv) == FAIL)
-		    return;
+		    goto theend;
 		d_ret = rettv->vval.v_dict;
 	    }
 
@@ -2090,6 +2098,12 @@
 		    }
 		    if (filtermap == FILTERMAP_MAP)
 		    {
+			if (type != NULL && check_typval_type(type->tt_member,
+							    &newtv, 0) == FAIL)
+			{
+			    clear_tv(&newtv);
+			    break;
+			}
 			// map(): replace the dict item value
 			clear_tv(&di->di_tv);
 			newtv.v_lock = 0;
@@ -2126,7 +2140,7 @@
 	    if (filtermap == FILTERMAP_MAPNEW)
 	    {
 		if (blob_copy(b, rettv) == FAIL)
-		    return;
+		    goto theend;
 		b_ret = rettv->vval.v_blob;
 	    }
 
@@ -2175,7 +2189,7 @@
 	    if (filtermap == FILTERMAP_MAPNEW)
 	    {
 		if (rettv_list_alloc(rettv) == FAIL)
-		    return;
+		    goto theend;
 		l_ret = rettv->vval.v_list;
 	    }
 	    // set_vim_var_nr() doesn't set the type
@@ -2218,6 +2232,13 @@
 		    }
 		    if (filtermap != FILTERMAP_FILTER)
 		    {
+			if (filtermap == FILTERMAP_MAP && type != NULL
+					  && check_typval_type(type->tt_member,
+							    &newtv, 0) == FAIL)
+			{
+			    clear_tv(&newtv);
+			    break;
+			}
 			// map(), mapnew(): always append the new value to the
 			// list
 			if (list_append_tv_move(filtermap == FILTERMAP_MAP
@@ -2256,6 +2277,12 @@
 		    }
 		    if (filtermap == FILTERMAP_MAP)
 		    {
+			if (type != NULL && check_typval_type(type->tt_member,
+							    &newtv, 0) == FAIL)
+			{
+			    clear_tv(&newtv);
+			    break;
+			}
 			// map(): replace the list item value
 			clear_tv(&li->li_tv);
 			newtv.v_lock = 0;
@@ -2281,6 +2308,10 @@
 
 	did_emsg |= save_did_emsg;
     }
+
+theend:
+    if (type != NULL)
+	clear_type_list(&type_list);
 }
 
 /*
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index 8dadb2c..c035558 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -1351,7 +1351,7 @@
       var ll: list<number>
       ll = [1, 2, 3]->map('"one"')
   END
-  CheckDefExecFailure(lines, 'E1012: Type mismatch; expected list<number> but got list<string>')
+  CheckDefExecFailure(lines, 'E1012: Type mismatch; expected number but got string')
 enddef
 
 def Test_cannot_use_let()
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 180070e..61d129e 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -331,27 +331,6 @@
   return filter(items, (_, val) => get({[val]: 1}, 'x'))
 enddef
 
-def Test_map_function_arg()
-  var lines =<< trim END
-      def MapOne(i: number, v: string): string
-        return i .. ':' .. v
-      enddef
-      var l = ['a', 'b', 'c']
-      map(l, MapOne)
-      assert_equal(['0:a', '1:b', '2:c'], l)
-  END
-  CheckDefAndScriptSuccess(lines)
-enddef
-
-def Test_map_item_type()
-  var lines =<< trim END
-      var l = ['a', 'b', 'c']
-      map(l, (k, v) => k .. '/' .. v )
-      assert_equal(['0/a', '1/b', '2/c'], l)
-  END
-  CheckDefAndScriptSuccess(lines)
-enddef
-
 def Test_filereadable()
   assert_false(filereadable(""))
   assert_false(filereadable(test_null_string()))
@@ -584,6 +563,45 @@
           ->str2nr()
 enddef
 
+def Test_map_function_arg()
+  var lines =<< trim END
+      def MapOne(i: number, v: string): string
+        return i .. ':' .. v
+      enddef
+      var l = ['a', 'b', 'c']
+      map(l, MapOne)
+      assert_equal(['0:a', '1:b', '2:c'], l)
+  END
+  CheckDefAndScriptSuccess(lines)
+enddef
+
+def Test_map_item_type()
+  var lines =<< trim END
+      var l = ['a', 'b', 'c']
+      map(l, (k, v) => k .. '/' .. v )
+      assert_equal(['0/a', '1/b', '2/c'], l)
+  END
+  CheckDefAndScriptSuccess(lines)
+
+  lines =<< trim END
+    var l: list<number> = [0]
+    echo map(l, (_, v) => [])
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1012: Type mismatch; expected number but got list<unknown>', 2)
+
+  lines =<< trim END
+    var l: list<number> = range(2)
+    echo map(l, (_, v) => [])
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1012: Type mismatch; expected number but got list<unknown>', 2)
+
+  lines =<< trim END
+    var d: dict<number> = {key: 0}
+    echo map(d, (_, v) => [])
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1012: Type mismatch; expected number but got list<unknown>', 2)
+enddef
+
 def Test_maparg()
   var lnum = str2nr(expand('<sflnum>'))
   map foo bar
diff --git a/src/version.c b/src/version.c
index 674f2b7..d001040 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2365,
+/**/
     2364,
 /**/
     2363,