diff --git a/src/query/service/src/servers/flight/v1/exchange/exchange_transform_shuffle.rs b/src/query/service/src/servers/flight/v1/exchange/exchange_transform_shuffle.rs
index 9c3242147c8d3..09495c2a8e31f 100644
--- a/src/query/service/src/servers/flight/v1/exchange/exchange_transform_shuffle.rs
+++ b/src/query/service/src/servers/flight/v1/exchange/exchange_transform_shuffle.rs
@@ -413,7 +413,8 @@ pub fn exchange_shuffle(
 
     let inputs_size = pipeline.output_len();
     let outputs_size = params.destination_ids.len();
-    let transform = ExchangeShuffleTransform::create(inputs_size, outputs_size, output_len);
+    // For an N-way merge, we need at least a buffer size of 2N.
+    let transform = ExchangeShuffleTransform::create(inputs_size, outputs_size, output_len * 2);
 
     let inputs = transform.get_inputs();
     let outputs = transform.get_outputs();