diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index dbf4c9d425c..3e98ae3cb19 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -97,6 +97,9 @@ Release 2.0.3-alpha - Unreleased
     HDFS-4021. Misleading error message when resources are low on the NameNode.
     (Christopher Conner via atm)
 
+    HDFS-4044. Duplicate ChecksumType definition in HDFS .proto files.
+    (Binglin Chang via suresh)
+
 Release 2.0.2-alpha - 2012-09-07 
   
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtoUtil.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtoUtil.java
index 0a4d20fa958..dd9beb535bc 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtoUtil.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/datatransfer/DataTransferProtoUtil.java
@@ -24,9 +24,9 @@ import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsProtoUtil;
 import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.BaseHeaderProto;
 import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.ChecksumProto;
-import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.ChecksumProto.ChecksumType;
 import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.ClientOperationHeaderProto;
 import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.OpWriteBlockProto;
+import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.ChecksumTypeProto;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.util.DataChecksum;
@@ -52,7 +52,7 @@ public abstract class DataTransferProtoUtil {
   }
 
   public static ChecksumProto toProto(DataChecksum checksum) {
-    ChecksumType type = ChecksumType.valueOf(checksum.getChecksumType().name());
+    ChecksumTypeProto type = ChecksumTypeProto.valueOf(checksum.getChecksumType().name());
     if (type == null) {
       throw new IllegalArgumentException(
           "Can't convert checksum to protobuf: " + checksum);
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/datatransfer.proto b/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/datatransfer.proto
index e02451a9aab..3ccad5efbe1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/datatransfer.proto
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/datatransfer.proto
@@ -54,12 +54,7 @@ message OpReadBlockProto {
 
 
 message ChecksumProto {
-  enum ChecksumType {
-    NULL = 0;
-    CRC32 = 1;
-    CRC32C = 2;
-  }
-  required ChecksumType type = 1;
+  required ChecksumTypeProto type = 1;
   required uint32 bytesPerChecksum = 2;
 }