diff --git a/src/blueapi/core/context.py b/src/blueapi/core/context.py
index a4526f6ce..78682ccf6 100644
--- a/src/blueapi/core/context.py
+++ b/src/blueapi/core/context.py
@@ -526,7 +526,7 @@ def _type_spec_for_function(
             )
         return new_args
 
-    def _convert_type(self, typ: type | Any, no_default: bool = True) -> type:
+    def _convert_type(self, typ: Any, no_default: bool = True) -> type:
         """
         Recursively convert a type to something that can be deserialised by
         pydantic. Bluesky protocols (and types that extend them) are replaced