diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index a324911765..e37b87cf34 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -367,6 +367,10 @@ Release 2.1.1-beta - UNRELEASED
 
   INCOMPATIBLE CHANGES
 
+    HADOOP-9944. Fix RpcRequestHeaderProto.callId to be sint32 rather than
+    uint32 since ipc.Client.CONNECTION_CONTEXT_CALL_ID is signed (i.e. -3) 
+    (acmurthy)
+
   NEW FEATURES
 
   IMPROVEMENTS
diff --git a/hadoop-common-project/hadoop-common/src/main/proto/ProtobufRpcEngine.proto b/hadoop-common-project/hadoop-common/src/main/proto/ProtobufRpcEngine.proto
index 7923e8ba71..a17e2078e9 100644
--- a/hadoop-common-project/hadoop-common/src/main/proto/ProtobufRpcEngine.proto
+++ b/hadoop-common-project/hadoop-common/src/main/proto/ProtobufRpcEngine.proto
@@ -60,8 +60,8 @@ message RequestHeaderProto {
    * ProtocolInfoProto) since they reuse the connection; in this case
    * the declaringClassProtocolName field is set to the ProtocolInfoProto
    */
-  required string declaringClassProtocolName = 3;
+  required string declaringClassProtocolName = 2;
   
   /** protocol version of class declaring the called method */
-  required uint64 clientProtocolVersion = 4;
+  required uint64 clientProtocolVersion = 3;
 }
diff --git a/hadoop-common-project/hadoop-common/src/main/proto/RpcHeader.proto b/hadoop-common-project/hadoop-common/src/main/proto/RpcHeader.proto
index 673883b23a..e8c4adac36 100644
--- a/hadoop-common-project/hadoop-common/src/main/proto/RpcHeader.proto
+++ b/hadoop-common-project/hadoop-common/src/main/proto/RpcHeader.proto
@@ -62,7 +62,7 @@ message RpcRequestHeaderProto { // the header for the RpcRequest
 
   optional RpcKindProto rpcKind = 1;
   optional OperationProto rpcOp = 2;
-  required uint32 callId = 3; // a sequence number that is sent back in response
+  required sint32 callId = 3; // a sequence number that is sent back in response
   required bytes clientId = 4; // Globally unique client ID
   // clientId + callId uniquely identifies a request
   // retry count, 1 means this is the first retry