diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
index a700837..acbd919 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
@@ -229,7 +229,7 @@
     private static boolean hackCanUseDictionaryFile(final Locale locale, final File f) {
         try {
             // Read the version of the file
-            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(f);
+            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(f, 0, f.length());
             final DictionaryHeader header = dictDecoder.readHeader();
 
             final String version = header.mDictionaryOptions.mAttributes.get(VERSION_KEY);
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
index b534ebe..25e1bcd 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderUtils.java
@@ -357,7 +357,7 @@
      * @return true if it's a binary dictionary, false otherwise
      */
     public static boolean isBinaryDictionary(final File file) {
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file);
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, 0, file.length());
         if (dictDecoder == null) {
             return false;
         }
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
index 989ca4b..90e7400 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
@@ -237,7 +237,7 @@
             final File file, final long offset, final long length)
             throws FileNotFoundException, IOException, UnsupportedFormatException {
         final byte[] buffer = new byte[HEADER_READING_BUFFER_SIZE];
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file,
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, offset, length,
                 new DictDecoder.DictionaryBufferFactory() {
                     @Override
                     public DictBuffer getDictionaryBuffer(File file)
@@ -251,8 +251,7 @@
                             inStream.close();
                         }
                     }
-                }
-        );
+                });
         if (dictDecoder == null) {
             return null;
         }
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index c7635ef..9abecbf 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -326,30 +326,34 @@
      * Returns new dictionary decoder.
      *
      * @param dictFile the dictionary file.
+     * @param offset the offset in the file.
+     * @param length the length of the file, in bytes.
      * @param bufferType The type of buffer, as one of USE_* in DictDecoder.
      * @return new dictionary decoder if the dictionary file exists, otherwise null.
      */
-    public static DictDecoder getDictDecoder(final File dictFile, final int bufferType) {
+    public static DictDecoder getDictDecoder(final File dictFile, final long offset,
+            final long length, final int bufferType) {
         if (dictFile.isDirectory()) {
             return new Ver4DictDecoder(dictFile, bufferType);
         } else if (dictFile.isFile()) {
-            return new Ver2DictDecoder(dictFile, bufferType);
+            return new Ver2DictDecoder(dictFile, offset, length, bufferType);
         }
         return null;
     }
 
-    public static DictDecoder getDictDecoder(final File dictFile,
-            final DictionaryBufferFactory factory) {
+    public static DictDecoder getDictDecoder(final File dictFile, final long offset,
+            final long length, final DictionaryBufferFactory factory) {
         if (dictFile.isDirectory()) {
             return new Ver4DictDecoder(dictFile, factory);
         } else if (dictFile.isFile()) {
-            return new Ver2DictDecoder(dictFile, factory);
+            return new Ver2DictDecoder(dictFile, offset, length, factory);
         }
         return null;
     }
 
-    public static DictDecoder getDictDecoder(final File dictFile) {
-        return getDictDecoder(dictFile, DictDecoder.USE_READONLY_BYTEBUFFER);
+    public static DictDecoder getDictDecoder(final File dictFile, final long offset,
+            final long length) {
+        return getDictDecoder(dictFile, offset, length, DictDecoder.USE_READONLY_BYTEBUFFER);
     }
 
     private FormatSpec() {
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
index bf776cf..ae1e443 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver2DictDecoder.java
@@ -116,13 +116,18 @@
     }
 
     protected final File mDictionaryBinaryFile;
+    protected final long mOffset;
+    protected final long mLength;
     // TODO: Remove mBufferFactory and mDictBuffer from this class members because they are now
     // used only for testing.
     private final DictionaryBufferFactory mBufferFactory;
     protected DictBuffer mDictBuffer;
 
-    /* package */ Ver2DictDecoder(final File file, final int factoryFlag) {
+    /* package */ Ver2DictDecoder(final File file, final long offset, final long length,
+            final int factoryFlag) {
         mDictionaryBinaryFile = file;
+        mOffset = offset;
+        mLength = length;
         mDictBuffer = null;
         if ((factoryFlag & MASK_DICTBUFFER) == USE_READONLY_BYTEBUFFER) {
             mBufferFactory = new DictionaryBufferFromReadOnlyByteBufferFactory();
@@ -135,8 +140,11 @@
         }
     }
 
-    /* package */ Ver2DictDecoder(final File file, final DictionaryBufferFactory factory) {
+    /* package */ Ver2DictDecoder(final File file, final long offset, final long length,
+            final DictionaryBufferFactory factory) {
         mDictionaryBinaryFile = file;
+        mOffset = offset;
+        mLength = length;
         mBufferFactory = factory;
     }
 
@@ -164,9 +172,9 @@
     public DictionaryHeader readHeader() throws IOException, UnsupportedFormatException {
         // dictType is not being used in dicttool. Passing an empty string.
         final BinaryDictionary binaryDictionary = new BinaryDictionary(
-                mDictionaryBinaryFile.getAbsolutePath(), 0 /* offset */,
-                mDictionaryBinaryFile.length() /* length */, true /* useFullEditDistance */,
-                null /* locale */, "" /* dictType */, false /* isUpdatable */);
+                mDictionaryBinaryFile.getAbsolutePath(), mOffset, mLength,
+                true /* useFullEditDistance */, null /* locale */, "" /* dictType */,
+                false /* isUpdatable */);
         final DictionaryHeader header = binaryDictionary.getHeader();
         binaryDictionary.close();
         if (header == null) {
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
index f4b16a7..fa51236 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
@@ -150,7 +150,7 @@
         binaryDictionary.flushWithGC();
         binaryDictionary.close();
 
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(dictFile);
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(dictFile, 0, dictFile.length());
         try {
             final FusionDictionary dict =
                     dictDecoder.readDictionaryBinary(false /* deleteDictIfBroken */);
diff --git a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
index e21e340..0ee0fb5 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/BinaryDictDecoderEncoderTests.java
@@ -251,7 +251,8 @@
 
         FusionDictionary dict = null;
         try {
-            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, bufferType);
+            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, 0, file.length(),
+                    bufferType);
             now = System.currentTimeMillis();
             dict = dictDecoder.readDictionaryBinary(false /* deleteDictIfBroken */);
             diff  = System.currentTimeMillis() - now;
@@ -413,7 +414,8 @@
 
         long now = -1, diff = -1;
         try {
-            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, bufferType);
+            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, 0, file.length(),
+                    bufferType);
             now = System.currentTimeMillis();
             dictDecoder.readUnigramsAndBigramsBinary(resultWords, resultFreqs, resultBigrams);
             diff = System.currentTimeMillis() - now;
@@ -537,7 +539,8 @@
         addBigrams(dict, words, bigrams);
         timeWritingDictToFile(file, dict, formatOptions);
 
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, DictDecoder.USE_BYTEARRAY);
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, 0, file.length(),
+                DictDecoder.USE_BYTEARRAY);
         try {
             dictDecoder.openDictBuffer();
         } catch (IOException e) {
diff --git a/tests/src/com/android/inputmethod/latin/makedict/Ver2DictDecoderTests.java b/tests/src/com/android/inputmethod/latin/makedict/Ver2DictDecoderTests.java
index a85753e..9dc2b10 100644
--- a/tests/src/com/android/inputmethod/latin/makedict/Ver2DictDecoderTests.java
+++ b/tests/src/com/android/inputmethod/latin/makedict/Ver2DictDecoderTests.java
@@ -68,7 +68,8 @@
         }
 
         assertNotNull(testFile);
-        final Ver2DictDecoder dictDecoder = new Ver2DictDecoder(testFile, factory);
+        final Ver2DictDecoder dictDecoder = new Ver2DictDecoder(testFile, 0, testFile.length(),
+                factory);
         try {
             dictDecoder.openDictBuffer();
         } catch (Exception e) {
@@ -110,7 +111,8 @@
             Log.e(TAG, "IOException while the creating temporary file", e);
         }
 
-        final Ver2DictDecoder dictDecoder = new Ver2DictDecoder(testFile, factory);
+        final Ver2DictDecoder dictDecoder = new Ver2DictDecoder(testFile, 0, testFile.length(),
+                factory);
 
         // the default return value of getBuffer() must be null.
         assertNull("the default return value of getBuffer() is not null",
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
index d1df81b..e31ac2a 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtils.java
@@ -192,7 +192,7 @@
                             new BufferedInputStream(new FileInputStream(decodedSpec.mFile)));
                 } else {
                     final DictDecoder dictDecoder = FormatSpec.getDictDecoder(decodedSpec.mFile,
-                            DictDecoder.USE_BYTEARRAY);
+                            0, decodedSpec.mFile.length(), DictDecoder.USE_BYTEARRAY);
                     if (report) {
                         System.out.println("Format : Binary dictionary format");
                         System.out.println("Packaging : " + decodedSpec.describeChain());
diff --git a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
index 80d71fc..68d7850 100644
--- a/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
+++ b/tools/dicttool/src/com/android/inputmethod/latin/dicttool/DictionaryMaker.java
@@ -264,7 +264,7 @@
     private static FusionDictionary readBinaryFile(final String binaryFilename)
             throws FileNotFoundException, IOException, UnsupportedFormatException {
         final File file = new File(binaryFilename);
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file);
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file, 0, file.length());
         return dictDecoder.readDictionaryBinary(false /* deleteDictIfBroken */);
     }
 
diff --git a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
index 7a4f6f7..faf00b4 100644
--- a/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
+++ b/tools/dicttool/tests/com/android/inputmethod/latin/dicttool/BinaryDictOffdeviceUtilsTests.java
@@ -77,7 +77,8 @@
             assertEquals("Wrong decode spec", BinaryDictOffdeviceUtils.COMPRESSION, step);
         }
         assertEquals("Wrong decode spec", 3, decodeSpec.mDecoderSpec.size());
-        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(decodeSpec.mFile);
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(decodeSpec.mFile, 0,
+                decodeSpec.mFile.length());
         final FusionDictionary resultDict =
                 dictDecoder.readDictionaryBinary(false /* deleteDictIfBroken */);
         assertEquals("Wrong version attribute", VERSION, resultDict.mOptions.mAttributes.get(