diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
index 78cf5a2fc..10115ac55 100644
--- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
+++ b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java
@@ -13,7 +13,6 @@ import seaweedfs.client.FilerProto;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.io.OutputStream;
 import java.net.URI;
 import java.util.EnumSet;
 import java.util.List;
@@ -112,9 +111,16 @@ public class SeaweedFileSystem extends FileSystem {
                 replicaPlacement = String.format("%03d", replication - 1);
             }
             int seaweedBufferSize = this.getConf().getInt(FS_SEAWEED_BUFFER_SIZE, FS_SEAWEED_DEFAULT_BUFFER_SIZE);
-            OutputStream outputStream = seaweedFileSystemStore.createFile(path, overwrite, permission,
+            SeaweedHadoopOutputStream outputStream = (SeaweedHadoopOutputStream) seaweedFileSystemStore.createFile(path, overwrite, permission,
                     seaweedBufferSize, replicaPlacement);
-            return new FSDataOutputStream(outputStream, statistics);
+            // Use custom FSDataOutputStream that delegates getPos() to our stream
+            return new FSDataOutputStream(outputStream, statistics) {
+                @Override
+                public long getPos() {
+                    // Delegate to SeaweedOutputStream's position tracking
+                    return outputStream.getPos();
+                }
+            };
         } catch (Exception ex) {
             LOG.error("Failed to create file: {} bufferSize:{} blockSize:{}", path, bufferSize, blockSize, ex);
             throw new IOException("Failed to create file: " + path, ex);
@@ -156,8 +162,15 @@ public class SeaweedFileSystem extends FileSystem {
         path = qualify(path);
         try {
             int seaweedBufferSize = this.getConf().getInt(FS_SEAWEED_BUFFER_SIZE, FS_SEAWEED_DEFAULT_BUFFER_SIZE);
-            OutputStream outputStream = seaweedFileSystemStore.createFile(path, false, null, seaweedBufferSize, "");
-            return new FSDataOutputStream(outputStream, statistics);
+            SeaweedHadoopOutputStream outputStream = (SeaweedHadoopOutputStream) seaweedFileSystemStore.createFile(path, false, null, seaweedBufferSize, "");
+            // Use custom FSDataOutputStream that delegates getPos() to our stream
+            return new FSDataOutputStream(outputStream, statistics) {
+                @Override
+                public long getPos() {
+                    // Delegate to SeaweedOutputStream's position tracking
+                    return outputStream.getPos();
+                }
+            };
         } catch (Exception ex) {
             LOG.error("Failed to append to file: {} bufferSize:{}", path, bufferSize, ex);
             throw new IOException("Failed to append to file: " + path, ex);