diff --git a/smee/mm/_config.py b/smee/mm/_config.py
index 054864a..a5e32f6 100644
--- a/smee/mm/_config.py
+++ b/smee/mm/_config.py
@@ -58,7 +58,7 @@ def __get_pydantic_json_schema__(
         cls,
         _core_schema: pydantic_core.core_schema.CoreSchema,
         handler: pydantic.GetJsonSchemaHandler,
-    ) -> pydantic.json_schema.JsonSchemaValue:
+    ) -> "pydantic.json_schema.JsonSchemaValue":
         return handler(pydantic_core.core_schema.str_schema())