diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index f17e0e7750f..e8f329102d1 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -243,6 +243,9 @@ Trunk (Unreleased)
 
     HDFS-4948. mvn site for hadoop-hdfs-nfs fails. (brandonli)
 
+    HDFS-5043. For HdfsFileStatus, set default value of childrenNum to -1
+    instead of 0 to avoid confusing applications. (brandonli)
+
 Release 2.3.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
index 88b0a97ead0..613edb1fa18 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java
@@ -1056,7 +1056,7 @@ public class PBHelper {
         fs.getPath().toByteArray(),
         fs.hasFileId()? fs.getFileId(): INodeId.GRANDFATHER_INODE_ID,
         fs.hasLocations() ? PBHelper.convert(fs.getLocations()) : null,
-        fs.hasChildrenNum() ? fs.getChildrenNum() : 0);
+        fs.hasChildrenNum() ? fs.getChildrenNum() : -1);
   }
 
   public static SnapshottableDirectoryStatus convert(
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java
index 3afc59b1d9b..840087393cd 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java
@@ -249,7 +249,7 @@ public class JsonUtil {
     final long fileId = m.containsKey("fileId") ? (Long) m.get("fileId")
         : INodeId.GRANDFATHER_INODE_ID;
     Long childrenNumLong = (Long) m.get("childrenNum");
-    final int childrenNum = (childrenNumLong == null) ? 0
+    final int childrenNum = (childrenNumLong == null) ? -1
             : childrenNumLong.intValue();
     return new HdfsFileStatus(len, type == PathType.DIRECTORY, replication,
         blockSize, mTime, aTime, permission, owner, group,
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto b/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto
index aac86387aef..085f629a8d3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto
@@ -179,7 +179,7 @@ message HdfsFileStatusProto {
 
   // Optional field for fileId
   optional uint64 fileId = 13 [default = 0]; // default as an invalid id
-  optional uint32 childrenNum = 14 [default = 0];
+  optional int32 childrenNum = 14 [default = -1];
 } 
 
 /**