diff --git a/java/com/facebook/soloader/ExoSoSource.java b/java/com/facebook/soloader/ExoSoSource.java
index 04fe0f5..be0ac63 100644
--- a/java/com/facebook/soloader/ExoSoSource.java
+++ b/java/com/facebook/soloader/ExoSoSource.java
@@ -137,7 +137,7 @@ public InputDso next() throws IOException {
         FileDso fileDso = mDsos[mCurrentDso++];
         FileInputStream dsoFile = new FileInputStream(fileDso.backingFile);
         try {
-          InputDso ret = new InputDsoStream(fileDso, dsoFile);
+          InputDso ret = new InputDso(fileDso, dsoFile);
           dsoFile = null; // Ownership transferred
           return ret;
         } finally {
diff --git a/java/com/facebook/soloader/ExtractFromZipSoSource.java b/java/com/facebook/soloader/ExtractFromZipSoSource.java
index f421c1a..93682f4 100644
--- a/java/com/facebook/soloader/ExtractFromZipSoSource.java
+++ b/java/com/facebook/soloader/ExtractFromZipSoSource.java
@@ -171,7 +171,7 @@ public InputDso next() throws IOException {
         ZipDso zipDso = mDsos[mCurrentDso++];
         InputStream is = mZipFile.getInputStream(zipDso.backingEntry);
         try {
-          InputDso ret = new InputDsoStream(zipDso, is);
+          InputDso ret = new InputDso(zipDso, is);
           is = null; // Transfer ownership
           return ret;
         } finally {
diff --git a/java/com/facebook/soloader/SysUtil.java b/java/com/facebook/soloader/SysUtil.java
index 5fd1672..f755ae9 100644
--- a/java/com/facebook/soloader/SysUtil.java
+++ b/java/com/facebook/soloader/SysUtil.java
@@ -29,7 +29,6 @@
 import android.system.OsConstants;
 import android.text.TextUtils;
 import dalvik.system.BaseDexClassLoader;
-import java.io.DataOutput;
 import java.io.File;
 import java.io.FileDescriptor;
 import java.io.FileNotFoundException;
@@ -303,7 +302,7 @@ public static void mkdirOrThrow(File dir) throws IOException {
    * @param buffer IO buffer to use
    * @return Number of bytes actually copied
    */
-  static int copyBytes(DataOutput os, InputStream is, int byteLimit, byte[] buffer)
+  static int copyBytes(RandomAccessFile os, InputStream is, int byteLimit, byte[] buffer)
       throws IOException {
     // Yes, this method is exactly the same as the above, just with a different type for `os'.
     int bytesCopied = 0;
diff --git a/java/com/facebook/soloader/UnpackingSoSource.java b/java/com/facebook/soloader/UnpackingSoSource.java
index fbfdf1f..3c37bf0 100644
--- a/java/com/facebook/soloader/UnpackingSoSource.java
+++ b/java/com/facebook/soloader/UnpackingSoSource.java
@@ -19,7 +19,6 @@
 import android.content.Context;
 import android.os.Parcel;
 import java.io.Closeable;
-import java.io.DataOutput;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -100,53 +99,23 @@ public Dso(String name, String hash) {
     }
   }
 
-  protected static interface InputDso extends Closeable {
-
-    public void write(DataOutput out, byte[] ioBuffer) throws IOException;
-
-    public Dso getDso();
-
-    public String getFileName();
-
-    public int available() throws IOException;
-
-    public InputStream getStream();
-  };
-
-  public static class InputDsoStream implements InputDso {
+  protected static final class InputDso implements Closeable {
     private final Dso dso;
     private final InputStream content;
 
-    public InputDsoStream(Dso dso, InputStream content) {
+    public InputDso(Dso dso, InputStream content) {
       this.dso = dso;
       this.content = content;
     }
 
-    @Override
-    public void write(DataOutput out, byte[] ioBuffer) throws IOException {
-      SysUtil.copyBytes(out, content, Integer.MAX_VALUE, ioBuffer);
-    }
-
-    @Override
     public Dso getDso() {
       return dso;
     }
 
-    @Override
-    public String getFileName() {
-      return dso.name;
-    }
-
-    @Override
     public int available() throws IOException {
       return content.available();
     }
 
-    @Override
-    public InputStream getStream() {
-      return content;
-    }
-
     @Override
     public void close() throws IOException {
       content.close();
@@ -220,8 +189,7 @@ private void deleteUnmentionedFiles(Dso[] dsos) throws IOException {
 
   private void extractDso(InputDso iDso, byte[] ioBuffer) throws IOException {
     LogUtil.i(TAG, "extracting DSO " + iDso.getDso().name);
-    File dsoFileName = new File(soDirectory, iDso.getFileName());
-
+    File dsoFileName = new File(soDirectory, iDso.getDso().name);
     if (dsoFileName.exists() && !dsoFileName.setWritable(true)) {
       throw new IOException(
           "error adding write permission to: "
@@ -247,7 +215,7 @@ private void extractDso(InputDso iDso, byte[] ioBuffer) throws IOException {
       if (sizeHint > 1) {
         SysUtil.fallocateIfSupported(dsoFile.getFD(), sizeHint);
       }
-      iDso.write(dsoFile, ioBuffer);
+      SysUtil.copyBytes(dsoFile, iDso.content, Integer.MAX_VALUE, ioBuffer);
       dsoFile.setLength(dsoFile.getFilePointer()); // In case we shortened file
       if (!dsoFileName.setExecutable(true /* allow exec... */, false /* ...for everyone */)) {
         throw new IOException("cannot make file executable: " + dsoFileName);