diff --git a/runtype/__init__.py b/runtype/__init__.py
index 95ba493..76cdfbd 100644
--- a/runtype/__init__.py
+++ b/runtype/__init__.py
@@ -1,6 +1,6 @@
 from .dataclass import dataclass
 from .dispatch import DispatchError, MultiDispatch
-from .validation import PythonTyping, TypeSystem, TypeMismatchError, assert_isa, isa, issubclass, validate_func
+from .validation import PythonTyping, TypeSystem, TypeMismatchError, assert_isa, isa, issubclass, validate_func, is_subtype
 from .pytypes import Constraint, String, Int
 
 __version__ = "0.3.1"
diff --git a/runtype/pytypes.py b/runtype/pytypes.py
index 488f10b..6607d03 100644
--- a/runtype/pytypes.py
+++ b/runtype/pytypes.py
@@ -166,6 +166,8 @@ def __init__(self, values):
         self.values = values
 
     def __le__(self, other):
+        if isinstance(other, OneOf):
+            return set(self.values) <= set(other.values)
         return NotImplemented
 
     def validate_instance(self, obj, sampler=None):
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 15f1e28..fe599a5 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -11,7 +11,7 @@
 import logging
 logging.basicConfig(level=logging.INFO)
 
-from runtype import Dispatch, DispatchError, dataclass, isa, issubclass, assert_isa, String, Int, validate_func
+from runtype import Dispatch, DispatchError, dataclass, isa, is_subtype, issubclass, assert_isa, String, Int, validate_func
 from runtype.dataclass import Configuration
 
 
@@ -106,6 +106,8 @@ def test_py38(self):
         assert isa('a', typing.Literal['a', 'b'])
         assert not isa('c', typing.Literal['a', 'b'])
 
+        assert is_subtype(typing.Literal[1], typing.Literal[1,2])
+
     def test_validate_func(self):
         @validate_func
         def f(a: int, b: str, c: List[int] = []):