diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
new file mode 100644
index 0000000..e2e1489
--- /dev/null
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.inputmethod.latin;
+
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.LargeTest;
+
+import com.android.inputmethod.latin.makedict.DictEncoder;
+import com.android.inputmethod.latin.makedict.FormatSpec;
+import com.android.inputmethod.latin.makedict.FusionDictionary;
+import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
+import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
+import com.android.inputmethod.latin.makedict.Ver3DictEncoder;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Locale;
+
+@LargeTest
+public class BinaryDictionaryTests extends AndroidTestCase {
+    private static final FormatSpec.FormatOptions FORMAT_OPTIONS =
+            new FormatSpec.FormatOptions(3 /* version */, true /* supportsDynamicUpdate */);
+    private static final String TEST_DICT_FILE_EXTENSION = ".testDict";
+    private static final String TEST_LOCALE = "test";
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        super.tearDown();
+    }
+
+    private File createEmptyDictionaryAndGetFile(final String filename) throws IOException,
+            UnsupportedFormatException {
+        final FusionDictionary dict = new FusionDictionary(new PtNodeArray(),
+                new FusionDictionary.DictionaryOptions(new HashMap<String,String>(), false, false));
+        final File file = File.createTempFile(filename, TEST_DICT_FILE_EXTENSION,
+                getContext().getCacheDir());
+        final DictEncoder dictEncoder = new Ver3DictEncoder(file);
+        dictEncoder.writeDictionary(dict, FORMAT_OPTIONS);
+        return file;
+    }
+
+    public void testIsValidDictionary() {
+        File dictFile = null;
+        try {
+            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary");
+        } catch (IOException e) {
+            fail("IOException while writing an initial dictionary : " + e);
+        } catch (UnsupportedFormatException e) {
+            fail("UnsupportedFormatException while writing an initial dictionary : " + e);
+        }
+        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
+                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
+                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
+        assertTrue("binaryDictionary must be valid for existing valid dictionary file.",
+                binaryDictionary.isValidDictionary());
+        binaryDictionary.close();
+        assertFalse("binaryDictionary must be invalid after closing.",
+                binaryDictionary.isValidDictionary());
+        dictFile.delete();
+        binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(), 0 /* offset */,
+                dictFile.length(), true /* useFullEditDistance */, Locale.getDefault(),
+                TEST_LOCALE, true /* isUpdatable */);
+        assertFalse("binaryDictionary must be invalid for not existing dictionary file.",
+                binaryDictionary.isValidDictionary());
+        binaryDictionary.close();
+    }
+}