diff --git a/siibra/volumes/parcellationmap.py b/siibra/volumes/parcellationmap.py
index 73209de3..982dfddf 100644
--- a/siibra/volumes/parcellationmap.py
+++ b/siibra/volumes/parcellationmap.py
@@ -162,7 +162,7 @@ def __init__(
     @property
     def key(self):
         _id = self.id
-        return create_key(_id.removeprefix("siibra-map-v0.0.1"))
+        return create_key(_id[len("siibra-map-v0.0.1"):])
 
     @property
     def species(self) -> Species: