diff --git a/transport-sctp/src/main/java/io/netty/channel/sctp/nio/NioSctpChannel.java b/transport-sctp/src/main/java/io/netty/channel/sctp/nio/NioSctpChannel.java
index 5dd52731e8..b0ef61007f 100644
--- a/transport-sctp/src/main/java/io/netty/channel/sctp/nio/NioSctpChannel.java
+++ b/transport-sctp/src/main/java/io/netty/channel/sctp/nio/NioSctpChannel.java
@@ -271,14 +271,14 @@ public class NioSctpChannel extends AbstractNioMessageChannel implements io.nett
         ByteBuf buffer = allocHandle.allocate(config().getAllocator());
         boolean free = true;
         try {
-            ByteBuffer data = buffer.nioBuffer(buffer.writerIndex(), buffer.writableBytes());
+            ByteBuffer data = buffer.internalNioBuffer(buffer.writerIndex(), buffer.writableBytes());
+            int pos = data.position();
+
             MessageInfo messageInfo = ch.receive(data, null, notificationHandler);
             if (messageInfo == null) {
                 return 0;
             }
-
-            data.flip();
-            buf.add(new SctpMessage(messageInfo, buffer.writerIndex(buffer.writerIndex() + data.remaining())));
+            buf.add(new SctpMessage(messageInfo, buffer.writerIndex(buffer.writerIndex() + (data.position() - pos))));
             free = false;
             return 1;
         } catch (Throwable cause) {
diff --git a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
index c95801c2ec..8fbc9a6e82 100644
--- a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
+++ b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
@@ -204,14 +204,14 @@ public final class NioDatagramChannel
         ByteBuf data = allocHandle.allocate(config.getAllocator());
         boolean free = true;
         try {
-            ByteBuffer nioData = data.nioBuffer(data.writerIndex(), data.writableBytes());
-
+            ByteBuffer nioData = data.internalNioBuffer(data.writerIndex(), data.writableBytes());
+            int pos = nioData.position();
             InetSocketAddress remoteAddress = (InetSocketAddress) ch.receive(nioData);
             if (remoteAddress == null) {
                 return 0;
             }
 
-            int readBytes = nioData.position();
+            int readBytes = nioData.position() - pos;
             data.writerIndex(data.writerIndex() + readBytes);
             allocHandle.record(readBytes);