diff --git a/cmd/zfs_object_agent/zettaobject/src/access_stats.rs b/cmd/zfs_object_agent/zettaobject/src/access_stats.rs
index 4604f7a86b40..446a23b96f24 100644
--- a/cmd/zfs_object_agent/zettaobject/src/access_stats.rs
+++ b/cmd/zfs_object_agent/zettaobject/src/access_stats.rs
@@ -122,7 +122,7 @@ impl<'a> OpInProgress<'a> {
 
         // This bucket mapping is equivalent to L_HISTO() macro in zfs.h
         let latency_bucket = std::cmp::min(
-            latency.next_power_of_two().trailing_zeros(),
+            latency.next_power_of_two().trailing_zeros() - 1,
             LATENCY_HISTOGRAM_BUCKETS - 1,
         ) as usize;