diff --git a/geocode/geocode.py b/geocode/geocode.py
index 3d747cf..d425c65 100644
--- a/geocode/geocode.py
+++ b/geocode/geocode.py
@@ -294,7 +294,7 @@ def reverse_geocode(self, latlons, entity, **kwargs):
         """
         entity = entity.lower()
         if entity == "gsp":
-            version = kwargs.pop("version", "20250109")
+            version = kwargs.pop("version", "20251204")
             return self.neso.reverse_geocode_gsp(latlons, version, **kwargs)
         elif entity == "llsoa":
             return self.ons_nrs.reverse_geocode_llsoa(latlons=latlons, **kwargs)