diff --git a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/FileBodyHandler.java b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/FileBodyHandler.java
index d2484bf146444..de2b80663a2f7 100644
--- a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/FileBodyHandler.java
+++ b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/FileBodyHandler.java
@@ -36,11 +36,7 @@ public File readFrom(Class<File> type, Type genericType,
         }
 
         try (OutputStream output = new BufferedOutputStream(new FileOutputStream(downloadedFile))) {
-            int read;
-            final byte[] buf = new byte[2048];
-            while ((read = entityStream.read(buf)) != -1) {
-                output.write(buf, 0, read);
-            }
+            entityStream.transferTo(output);
         }
 
         return downloadedFile;
diff --git a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/InputStreamMessageBodyHandler.java b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/InputStreamMessageBodyHandler.java
index b5eb4010aadc2..383464b513a18 100644
--- a/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/InputStreamMessageBodyHandler.java
+++ b/independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/providers/serialisers/InputStreamMessageBodyHandler.java
@@ -34,11 +34,7 @@ public void writeTo(InputStream inputStream, Class<?> type, Type genericType, An
 
     protected void writeTo(InputStream inputStream, OutputStream entityStream) throws IOException {
         try {
-            byte[] buffer = new byte[8192];
-            int c;
-            while ((c = inputStream.read(buffer)) != -1) {
-                entityStream.write(buffer, 0, c);
-            }
+            inputStream.transferTo(entityStream);
         } finally {
             try {
                 inputStream.close();