diff --git a/compio-io/src/util/mod.rs b/compio-io/src/util/mod.rs
index b5fc6226..f471602b 100644
--- a/compio-io/src/util/mod.rs
+++ b/compio-io/src/util/mod.rs
@@ -47,6 +47,7 @@ pub async fn copy<R: AsyncRead, W: AsyncWrite>(reader: &mut R, writer: &mut W) -
         let res;
         (res, buf) = writer.write_all(buf).await.into();
         res?;
+        buf.clear();
     }
 
     Ok(total)