diff --git a/providers/multipart/src/main/java/org/jboss/resteasy/plugins/providers/multipart/AbstractMultipartWriter.java b/providers/multipart/src/main/java/org/jboss/resteasy/plugins/providers/multipart/AbstractMultipartWriter.java
index 68b3fd3dd..bcea72b4f 100644
--- a/providers/multipart/src/main/java/org/jboss/resteasy/plugins/providers/multipart/AbstractMultipartWriter.java
+++ b/providers/multipart/src/main/java/org/jboss/resteasy/plugins/providers/multipart/AbstractMultipartWriter.java
@@ -13,6 +13,7 @@ import javax.ws.rs.core.MultivaluedMap;
 import javax.ws.rs.ext.MessageBodyWriter;
 import javax.ws.rs.ext.Providers;
 
+import org.jboss.resteasy.plugins.providers.ByteArrayProvider;
 import org.jboss.resteasy.resteasy_jaxrs.i18n.LogMessages;
 import org.jboss.resteasy.specimpl.MultivaluedMapImpl;
 import org.jboss.resteasy.spi.AsyncMessageBodyWriter;
@@ -115,7 +116,7 @@ public class AbstractMultipartWriter
         Object entity = part.getEntity();
         Class<?> entityType = part.getType();
         Type entityGenericType = part.getGenericType();
-        AsyncMessageBodyWriter writer = (AsyncMessageBodyWriter) workers.getMessageBodyWriter(entityType, entityGenericType, null, part.getMediaType());
+        AsyncMessageBodyWriter writer = new ByteArrayProvider();
         LogMessages.LOGGER.debugf("MessageBodyWriter: %s", writer.getClass().getName());
         return entityStream.asyncWrite(boundaryBytes)
                 .thenCompose(v -> entityStream.asyncWrite(LINE_SEPARATOR_BYTES))