diff --git a/tokio/src/io/util/copy.rs b/tokio/src/io/util/copy.rs
index d7fca2c37..d0ab7cb14 100644
--- a/tokio/src/io/util/copy.rs
+++ b/tokio/src/io/util/copy.rs
@@ -23,7 +23,7 @@ impl CopyBuffer {
             pos: 0,
             cap: 0,
             amt: 0,
-            buf: vec![0; 2048].into_boxed_slice(),
+            buf: vec![0; super::DEFAULT_BUF_SIZE].into_boxed_slice(),
         }
     }