diff --git a/src/canonicaljson/__init__.py b/src/canonicaljson/__init__.py
index d481262..8337de1 100644
--- a/src/canonicaljson/__init__.py
+++ b/src/canonicaljson/__init__.py
@@ -52,7 +52,9 @@ def __call__(self, *args: Any, **kwargs: Any) -> "Encoder":
 
 
 class JsonLibrary(Protocol):
-    JSONEncoder: Encoder
+    @property
+    def JSONEncoder(self) -> Encoder:
+        pass
 
 
 # Declare these in the module scope, but they get configured in