diff --git a/botorch/posteriors/fully_bayesian.py b/botorch/posteriors/fully_bayesian.py
index a286976c7a..3084a743d2 100644
--- a/botorch/posteriors/fully_bayesian.py
+++ b/botorch/posteriors/fully_bayesian.py
@@ -138,6 +138,6 @@ def batch_range(self) -> Tuple[int, int]:
         candidate produces same value regardless of its position on the t-batch.
         """
         if self._is_mt:
-            return (0, -3)
-        else:
             return (0, -2)
+        else:
+            return (0, -1)