diff --git a/src/blib2to3/pytree.py b/src/blib2to3/pytree.py
index 7843467..001652d 100644
--- a/src/blib2to3/pytree.py
+++ b/src/blib2to3/pytree.py
@@ -52,7 +52,7 @@ def type_repr(type_num: int) -> Union[Text, int]:
     return _type_reprs.setdefault(type_num, type_num)
 
 
-_P = TypeVar("_P")
+_P = TypeVar("_P", bound="Base")
 
 NL = Union["Node", "Leaf"]
 Context = Tuple[Text, Tuple[int, int]]
@@ -109,6 +109,9 @@ def _eq(self: _P, other: _P) -> bool:
         """
         raise NotImplementedError
 
+    def __deepcopy__(self: _P, memo: Any) -> _P:
+        return self.clone()
+
     def clone(self: _P) -> _P:
         """
         Return a cloned (deep) copy of self.
diff --git a/tests/data/pattern_matching_extras.py b/tests/data/pattern_matching_extras.py
index b17922d..614e66a 100644
--- a/tests/data/pattern_matching_extras.py
+++ b/tests/data/pattern_matching_extras.py
@@ -1,3 +1,5 @@
+import match
+
 match something:
     case [a as b]:
         print(b)
@@ -7,3 +9,21 @@
         print(b)
     case Point(int() as x, int() as y):
         print(x, y)
+
+
+match = 1
+case: int = re.match(something)
+
+match re.match(case):
+    case type("match", match):
+        pass
+    case match:
+        pass
+
+
+def func(match: case, case: match) -> case:
+    match Something():
+        case another:
+            ...
+        case func(match, case):
+            ...