diff --git a/native/jni/NativeFileList.mk b/native/jni/NativeFileList.mk
index 68d2bbd..b896f38 100644
--- a/native/jni/NativeFileList.mk
+++ b/native/jni/NativeFileList.mk
@@ -131,6 +131,7 @@
     suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table_test.cpp \
     suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer_test.cpp \
     suggest/policyimpl/dictionary/utils/byte_array_utils_test.cpp \
+    suggest/policyimpl/dictionary/utils/format_utils_test.cpp \
     suggest/policyimpl/dictionary/utils/sparse_table_test.cpp \
     suggest/policyimpl/dictionary/utils/trie_map_test.cpp \
     suggest/policyimpl/utils/damerau_levenshtein_edit_distance_policy_test.cpp \
diff --git a/native/jni/tests/suggest/policyimpl/dictionary/utils/format_utils_test.cpp b/native/jni/tests/suggest/policyimpl/dictionary/utils/format_utils_test.cpp
new file mode 100644
index 0000000..15f560c
--- /dev/null
+++ b/native/jni/tests/suggest/policyimpl/dictionary/utils/format_utils_test.cpp
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#include "suggest/policyimpl/dictionary/utils/format_utils.h"
+
+#include <gtest/gtest.h>
+
+#include <vector>
+
+#include "utils/byte_array_view.h"
+
+namespace latinime {
+namespace {
+
+TEST(FormatUtilsTest, TestMagicNumber) {
+    EXPECT_EQ(0x9BC13AFE, FormatUtils::MAGIC_NUMBER) << "Magic number must not be changed.";
+}
+
+const std::vector<uint8_t> getBuffer(const int magicNumber, const int version, const uint16_t flags,
+        const size_t headerSize) {
+    std::vector<uint8_t> buffer;
+    buffer.push_back(magicNumber >> 24);
+    buffer.push_back(magicNumber >> 16);
+    buffer.push_back(magicNumber >> 8);
+    buffer.push_back(magicNumber);
+
+    buffer.push_back(version >> 8);
+    buffer.push_back(version);
+
+    buffer.push_back(flags >> 8);
+    buffer.push_back(flags);
+
+    buffer.push_back(headerSize >> 24);
+    buffer.push_back(headerSize >> 16);
+    buffer.push_back(headerSize >> 8);
+    buffer.push_back(headerSize);
+    return buffer;
+}
+
+TEST(FormatUtilsTest, TestDetectFormatVersion) {
+    EXPECT_EQ(FormatUtils::UNKNOWN_VERSION,
+            FormatUtils::detectFormatVersion(ReadOnlyByteArrayView()));
+
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER, FormatUtils::VERSION_2, 0, 0);
+        EXPECT_EQ(FormatUtils::VERSION_2, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size())));
+    }
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER, FormatUtils::VERSION_4, 0, 0);
+        EXPECT_EQ(FormatUtils::VERSION_4, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size())));
+    }
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER, FormatUtils::VERSION_4_DEV, 0, 0);
+        EXPECT_EQ(FormatUtils::VERSION_4_DEV, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size())));
+    }
+
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER - 1, FormatUtils::VERSION_2, 0, 0);
+        EXPECT_EQ(FormatUtils::UNKNOWN_VERSION, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size())));
+    }
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER, 100, 0, 0);
+        EXPECT_EQ(FormatUtils::UNKNOWN_VERSION, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size())));
+    }
+    {
+        const std::vector<uint8_t> buffer =
+                getBuffer(FormatUtils::MAGIC_NUMBER, FormatUtils::VERSION_2, 0, 0);
+        EXPECT_EQ(FormatUtils::UNKNOWN_VERSION, FormatUtils::detectFormatVersion(
+                ReadOnlyByteArrayView(buffer.data(), buffer.size() - 1)));
+    }
+}
+
+}  // namespace
+}  // namespace latinime