diff --git a/src/mito2/src/read/merge.rs b/src/mito2/src/read/merge.rs
index 917146391b08..144874984bc4 100644
--- a/src/mito2/src/read/merge.rs
+++ b/src/mito2/src/read/merge.rs
@@ -902,6 +902,47 @@ mod tests {
         .await;
     }
 
+    #[tokio::test]
+    async fn test_merge_many_duplicates() {
+        let mut builder = MergeReaderBuilder::new();
+        builder.batch_size(3);
+        for i in 0..10 {
+            let batches: Vec<_> = (0..8)
+                .map(|ts| new_batch(b"k1", &[ts], &[i], &[OpType::Put], &[100]))
+                .collect();
+            let reader = VecBatchReader::new(&batches);
+            builder.push_batch_reader(Box::new(reader));
+        }
+        let mut reader = builder.build().await.unwrap();
+        check_reader_result(
+            &mut reader,
+            &[
+                new_batch(
+                    b"k1",
+                    &[0, 1, 2],
+                    &[9, 9, 9],
+                    &[OpType::Put, OpType::Put, OpType::Put],
+                    &[100, 100, 100],
+                ),
+                new_batch(
+                    b"k1",
+                    &[3, 4, 5],
+                    &[9, 9, 9],
+                    &[OpType::Put, OpType::Put, OpType::Put],
+                    &[100, 100, 100],
+                ),
+                new_batch(
+                    b"k1",
+                    &[6, 7],
+                    &[9, 9],
+                    &[OpType::Put, OpType::Put],
+                    &[100, 100],
+                ),
+            ],
+        )
+        .await;
+    }
+
     #[tokio::test]
     async fn test_merge_more_than_batch_size() {
         let batches: Vec<_> = (0..MIN_BATCH_SIZE as i64 * 2)