@@ -107,6 +107,8 @@ def visit_unbound_type(self, t: UnboundType) -> Type:
             elif fullname == 'typing.Any':
                 return AnyType()
             elif fullname == 'typing.Tuple':
+                if len(t.args) == 0:  # Bare 'Tuple' is same as 'tuple'
+                    return self.builtin_type('builtins.tuple', [AnyType()])
                 if len(t.args) == 2 and isinstance(t.args[1], EllipsisType):
                     # Tuple[T, ...] (uniform, variable-length tuple)
                     node = self.lookup_fqn_func('builtins.tuple')
 
@@ -820,3 +820,20 @@ from typing import List, Tuple
 def f() -> Tuple[List[str], ...]:
     return ([],)
 [builtins fixtures/tuple.pyi]
+
+[case testTupleWithoutArgs]
+from typing import Tuple
+def f(a: Tuple) -> None: pass
+f(())
+f((1,))
+f(('', ''))
+[builtins fixtures/tuple.pyi]
+
+[case testTupleSingleton]
+# flags: --fast-parser
+from typing import Tuple
+def f(a: Tuple[()]) -> None: pass
+f(())
+f((1,))  # E
+f(('', ''))  # #
+[builtins fixtures/tuple.pyi]
@@ -25,5 +25,3 @@ T = TypeVar('T')
 class list(Sequence[T], Generic[T]): pass
 
 def sum(iterable: Iterable[T], start: T = None) -> T: pass
-
-True = bool()