diff --git a/mypy/build.py b/mypy/build.py
index b3ca8d06916d..ed7843e405c9 100644
--- a/mypy/build.py
+++ b/mypy/build.py
@@ -837,6 +837,8 @@ def parse_file(
             self.errors.ignored_files.add(path)
         tree = parse(source, path, id, self.errors, options=options)
         tree._fullname = id
+        if options.use_builtins_fixtures and id in CORE_BUILTIN_MODULES:
+            tree._is_typeshed_file = True
         self.add_stats(
             files_parsed=1,
             modules_parsed=int(not tree.is_stub),
diff --git a/mypy/checker.py b/mypy/checker.py
index 979a55b223c9..2bbb25dec351 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -1066,6 +1066,9 @@ def check_func_item(
 
         If type_override is provided, use it as the function type.
         """
+        if defn.is_synthetic():
+            return
+
         self.dynamic_funcs.append(defn.is_dynamic() and not type_override)
 
         with self.enter_partial_types(is_function=True):
@@ -1324,9 +1327,7 @@ def check_func_def(
                 )
 
                 # Ignore plugin generated methods, these usually don't need any bodies.
-                if defn.info is not FUNC_NO_INFO and (
-                    defn.name not in defn.info.names or defn.info.names[defn.name].plugin_generated
-                ):
+                if defn.is_synthetic():
                     show_error = False
 
                 # Ignore also definitions that appear in `if TYPE_CHECKING: ...` blocks.
@@ -4875,6 +4876,8 @@ def visit_del_stmt(self, s: DelStmt) -> None:
                     )
 
     def visit_decorator(self, e: Decorator) -> None:
+        if e.func.is_synthetic():
+            return
         for d in e.decorators:
             if isinstance(d, RefExpr):
                 if d.fullname == "typing.no_type_check":
diff --git a/mypy/nodes.py b/mypy/nodes.py
index 17e06613d1e3..81e242c68fbf 100644
--- a/mypy/nodes.py
+++ b/mypy/nodes.py
@@ -710,6 +710,12 @@ def __init__(
             if self.arguments[i] is None and i < self.max_fixed_argc():
                 self.min_args = i + 1
 
+    def is_synthetic(self) -> bool:
+        if self.info is FUNC_NO_INFO:
+            return False
+        sym = self.info.names.get(self.name)
+        return not sym or sym.plugin_generated
+
     def max_fixed_argc(self) -> int:
         return self.max_pos
 
diff --git a/mypy/plugins/attrs.py b/mypy/plugins/attrs.py
index 81f96c088ecd..dcd954606205 100644
--- a/mypy/plugins/attrs.py
+++ b/mypy/plugins/attrs.py
@@ -645,6 +645,11 @@ def _attribute_from_attrib_maker(
                 rvalue,
                 code=LITERAL_REQ,
             )
+
+    if init_type is None and ctx.api.options.disallow_untyped_defs:
+        assert lhs.node is not None
+        ctx.api.msg.need_annotation_for_var(lhs.node, stmt)
+
     name = unmangle(lhs.name)
     return Attribute(
         name, alias, ctx.cls.info, attr_has_default, init, kw_only, converter_info, stmt, init_type
diff --git a/test-data/unit/check-dataclasses.test b/test-data/unit/check-dataclasses.test
index 107298875761..5b5221dfd58d 100644
--- a/test-data/unit/check-dataclasses.test
+++ b/test-data/unit/check-dataclasses.test
@@ -2544,3 +2544,18 @@ class Base:
 class Child(Base):
     y: int
 [builtins fixtures/dataclasses.pyi]
+
+[case testDataclassDisallowAny]
+# flags: --disallow-any-explicit --disallow-any-decorated
+
+from dataclasses import dataclass
+from typing import Any
+
+# Ensures that when Any-typed fields end up in synthetic functions,
+# those functions are not flagged since there's nothing the user can do about that
+@dataclass
+class C:
+    a: Any  # E: Explicit "Any" is not allowed
+
+[typing fixtures/typing-full.pyi]
+[builtins fixtures/dataclasses.pyi]
diff --git a/test-data/unit/check-flags.test b/test-data/unit/check-flags.test
index 04adaca317c1..3d8255629793 100644
--- a/test-data/unit/check-flags.test
+++ b/test-data/unit/check-flags.test
@@ -1303,18 +1303,18 @@ def f(i: int, s):
 main:3: error: Function is missing a return type annotation
 main:3: error: Function is missing a type annotation for one or more arguments
 
-[case testDisallowIncompleteDefsAttrsNoAnnotations]
-# flags: --disallow-incomplete-defs
+[case testDisallowUntypedDefsAttrsNoAnnotations]
+# flags: --disallow-untyped-defs
 import attrs
 
 @attrs.define
 class Unannotated:
-    foo = attrs.field()
+    foo = attrs.field()  # E: Need type annotation for "foo"
 
 [builtins fixtures/plugin_attrs.pyi]
 
-[case testDisallowIncompleteDefsAttrsWithAnnotations]
-# flags: --disallow-incomplete-defs
+[case testDisallowUntypedDefsAttrsWithAnnotations]
+# flags: --disallow-untyped-defs
 import attrs
 
 @attrs.define
@@ -1323,14 +1323,14 @@ class Annotated:
 
 [builtins fixtures/plugin_attrs.pyi]
 
-[case testDisallowIncompleteDefsAttrsPartialAnnotations]
-# flags: --disallow-incomplete-defs
+[case testDisallowUntypedDefsAttrsPartialAnnotations]
+# flags: --disallow-untyped-defs
 import attrs
 
 @attrs.define
-class PartiallyAnnotated:  # E: Function is missing a type annotation for one or more arguments
+class PartiallyAnnotated:
     bar: int = attrs.field()
-    baz = attrs.field()
+    baz = attrs.field()  # E: Need type annotation for "baz"
 
 [builtins fixtures/plugin_attrs.pyi]