From 221a7f34cbfdc0dafe7f84042f2a707cbfdbf60f Mon Sep 17 00:00:00 2001
From: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Date: Thu, 6 Jan 2022 01:44:10 -0800
Subject: [PATCH] Fix PEP 585 type aliases in stubs (#11918)

Fixes #11859

Co-authored-by: hauntsaninja <>
---
 mypy/semanal.py                         |  1 +
 test-data/unit/check-generic-alias.test | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/mypy/semanal.py b/mypy/semanal.py
index a948b5c8834d..01f39756ba11 100644
--- a/mypy/semanal.py
+++ b/mypy/semanal.py
@@ -4089,6 +4089,7 @@ def analyze_type_application(self, expr: IndexExpr) -> None:
                 name = target.type.fullname
                 if (alias.no_args and  # this avoids bogus errors for already reported aliases
                         name in get_nongen_builtins(self.options.python_version) and
+                        not self.is_stub_file and
                         not alias.normalized):
                     self.fail(no_subscript_builtin_alias(name, propose_alt=False), expr)
         # ...or directly.
diff --git a/test-data/unit/check-generic-alias.test b/test-data/unit/check-generic-alias.test
index bfef0f5c5086..0f8be72c556f 100644
--- a/test-data/unit/check-generic-alias.test
+++ b/test-data/unit/check-generic-alias.test
@@ -285,3 +285,14 @@ class C(list[int]):
     pass
 d: type[str]
 [builtins fixtures/list.pyi]
+
+
+[case testTypeAliasWithBuiltinListAliasInStub]
+# flags: --python-version 3.6
+import m
+reveal_type(m.a()[0])  # N: Revealed type is "builtins.int*"
+
+[file m.pyi]
+List = list
+a = List[int]
+[builtins fixtures/list.pyi]