diff --git a/vizier/_src/algorithms/optimizers/eagle_strategy.py b/vizier/_src/algorithms/optimizers/eagle_strategy.py
index 933e8c699..cc0ae6a04 100644
--- a/vizier/_src/algorithms/optimizers/eagle_strategy.py
+++ b/vizier/_src/algorithms/optimizers/eagle_strategy.py
@@ -577,7 +577,7 @@ def _loop_body(i, args):
     )
 
   @property
-  def suggestion_batch_size(self) -> int:
+  def suggestion_batch_size(self) -> int | None:
     """The number of suggestions returned at each call of 'suggest'."""
     return self.batch_size