diff --git a/buffer/src/main/java/io/netty/buffer/DefaultByteBufHolder.java b/buffer/src/main/java/io/netty/buffer/DefaultByteBufHolder.java
index 81acbee1f7..62a23ea6f0 100644
--- a/buffer/src/main/java/io/netty/buffer/DefaultByteBufHolder.java
+++ b/buffer/src/main/java/io/netty/buffer/DefaultByteBufHolder.java
@@ -27,10 +27,6 @@ public class DefaultByteBufHolder implements ByteBufHolder {
         if (data == null) {
             throw new NullPointerException("data");
         }
-        if (data.unwrap() != null && !(data instanceof SwappedByteBuf)) {
-            throw new IllegalArgumentException("Only not-derived ByteBuf instance are supported, you used: "
-                    + data.getClass().getSimpleName());
-        }
         this.data = data;
     }
 
diff --git a/codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java b/codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java
index b3aefc160b..aa2497438f 100644
--- a/codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java
+++ b/codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java
@@ -208,7 +208,7 @@ public class SpdySessionHandler
                 if (newWindowSize < 0) {
                     while (spdyDataFrame.data().readableBytes() > initialReceiveWindowSize) {
                         SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
-                                spdyDataFrame.data().readSlice(initialReceiveWindowSize));
+                                spdyDataFrame.data().readSlice(initialReceiveWindowSize).retain());
                         ctx.nextOutboundMessageBuffer().add(partialDataFrame);
                         ctx.flush();
                     }
@@ -525,7 +525,7 @@ public class SpdySessionHandler
 
                         // Create a partial data frame whose length is the current window size
                         SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
-                                spdyDataFrame.data().readSlice(sendWindowSize));
+                                spdyDataFrame.data().readSlice(sendWindowSize).retain());
 
                         // Enqueue the remaining data (will be the first frame queued)
                         spdySession.putPendingWrite(streamID, spdyDataFrame);
@@ -849,7 +849,7 @@ public class SpdySessionHandler
 
                     // Create a partial data frame whose length is the current window size
                     SpdyDataFrame partialDataFrame = new DefaultSpdyDataFrame(streamID,
-                            spdyDataFrame.data().readSlice(newWindowSize));
+                            spdyDataFrame.data().readSlice(newWindowSize).retain());
 
                     // The transfer window size is pre-decremented when sending a data frame downstream.
                     // Close the stream on write failures that leaves the transfer window in a corrupt state.