diff --git a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
index 334ebb37d..2cbce045d 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableBinaryDictionary.java
@@ -114,7 +114,8 @@ abstract public class ExpandableBinaryDictionary extends Dictionary {
     private boolean needsToMigrateDictionary(final int formatVersion) {
         // When we bump up the dictionary format version, the old version should be added to here
         // for supporting migration. Note that native code has to support reading such formats.
-        return formatVersion == FormatSpec.VERSION4_ONLY_FOR_TESTING;
+        return formatVersion == FormatSpec.VERSION4_ONLY_FOR_TESTING
+                || formatVersion == FormatSpec.VERSION401;
     }
 
     public boolean isValidDictionaryLocked() {
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index f5f072b7a..a2ae74b20 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -192,8 +192,9 @@ public final class FormatSpec {
     public static final int VERSION2 = 2;
     // Dictionary version used for testing.
     public static final int VERSION4_ONLY_FOR_TESTING = 399;
-    public static final int VERSION4 = 401;
-    public static final int VERSION4_DEV = 402;
+    public static final int VERSION401 = 401;
+    public static final int VERSION4 = 402;
+    public static final int VERSION4_DEV = 403;
     static final int MINIMUM_SUPPORTED_VERSION = VERSION2;
     static final int MAXIMUM_SUPPORTED_VERSION = VERSION4_DEV;
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
index 281c5a818..75f4fef90 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
@@ -139,6 +139,8 @@ class HeaderPolicy : public DictionaryHeaderStructurePolicy {
         switch (mDictFormatVersion) {
             case FormatUtils::VERSION_2:
                 return FormatUtils::VERSION_2;
+            case FormatUtils::VERSION_401:
+                return FormatUtils::VERSION_401;
             case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
                 return FormatUtils::VERSION_4_ONLY_FOR_TESTING;
             case FormatUtils::VERSION_4:
@@ -247,7 +249,7 @@ class HeaderPolicy : public DictionaryHeaderStructurePolicy {
     }
 
     bool supportsBeginningOfSentence() const {
-        return mDictFormatVersion == FormatUtils::VERSION_4_DEV;
+        return mDictFormatVersion > FormatUtils::VERSION_401;
     }
 
  private:
diff --git a/native/jni/src/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
index a8f8f284b..b13ad1879 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
@@ -98,6 +98,7 @@ typedef DictionaryHeaderStructurePolicy::AttributeMap AttributeMap;
         case FormatUtils::VERSION_2:
             // Version 2 dictionary writing is not supported.
             return false;
+        case FormatUtils::VERSION_401:
         case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
         case FormatUtils::VERSION_4:
         case FormatUtils::VERSION_4_DEV:
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/dictionary_structure_with_buffer_policy_factory.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/dictionary_structure_with_buffer_policy_factory.cpp
index f93d2894c..93e330a2a 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/dictionary_structure_with_buffer_policy_factory.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/dictionary_structure_with_buffer_policy_factory.cpp
@@ -57,13 +57,14 @@ namespace latinime {
                 const DictionaryHeaderStructurePolicy::AttributeMap *const attributeMap) {
     FormatUtils::FORMAT_VERSION dictFormatVersion = FormatUtils::getFormatVersion(formatVersion);
     switch (dictFormatVersion) {
-        case FormatUtils::VERSION_4: {
+        case FormatUtils::VERSION_401: {
             return newPolicyForOnMemoryV4Dict<backward::v401::Ver4DictConstants,
                     backward::v401::Ver4DictBuffers,
                     backward::v401::Ver4DictBuffers::Ver4DictBuffersPtr,
                     backward::v401::Ver4PatriciaTriePolicy>(
                             dictFormatVersion, locale, attributeMap);
         }
+        case FormatUtils::VERSION_4:
         case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
         case FormatUtils::VERSION_4_DEV: {
             return newPolicyForOnMemoryV4Dict<Ver4DictConstants, Ver4DictBuffers,
@@ -115,13 +116,14 @@ template<class DictConstants, class DictBuffers, class DictBuffersPtr, class Str
         case FormatUtils::VERSION_2:
             AKLOGE("Given path is a directory but the format is version 2. path: %s", path);
             break;
-        case FormatUtils::VERSION_4: {
+        case FormatUtils::VERSION_401: {
             return newPolicyForV4Dict<backward::v401::Ver4DictConstants,
                     backward::v401::Ver4DictBuffers,
                     backward::v401::Ver4DictBuffers::Ver4DictBuffersPtr,
                     backward::v401::Ver4PatriciaTriePolicy>(
                             headerFilePath, formatVersion, std::move(mmappedBuffer));
         }
+        case FormatUtils::VERSION_4:
         case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
         case FormatUtils::VERSION_4_DEV: {
             return newPolicyForV4Dict<Ver4DictConstants, Ver4DictBuffers,
@@ -177,6 +179,7 @@ template<class DictConstants, class DictBuffers, class DictBuffersPtr, class Str
         case FormatUtils::VERSION_2:
             return DictionaryStructureWithBufferPolicy::StructurePolicyPtr(
                     new PatriciaTriePolicy(std::move(mmappedBuffer)));
+        case FormatUtils::VERSION_401:
         case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
         case FormatUtils::VERSION_4:
         case FormatUtils::VERSION_4_DEV:
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
index 105363db5..a04551a44 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/dict_file_writing_utils.cpp
@@ -41,11 +41,12 @@ const char *const DictFileWritingUtils::TEMP_FILE_SUFFIX_FOR_WRITING_DICT_FILE =
     TimeKeeper::setCurrentTime();
     const FormatUtils::FORMAT_VERSION formatVersion = FormatUtils::getFormatVersion(dictVersion);
     switch (formatVersion) {
-        case FormatUtils::VERSION_4:
+        case FormatUtils::VERSION_401:
             return createEmptyV4DictFile<backward::v401::Ver4DictConstants,
                     backward::v401::Ver4DictBuffers,
                     backward::v401::Ver4DictBuffers::Ver4DictBuffersPtr>(
                             filePath, localeAsCodePointVector, attributeMap, formatVersion);
+        case FormatUtils::VERSION_4:
         case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
         case FormatUtils::VERSION_4_DEV:
             return createEmptyV4DictFile<Ver4DictConstants, Ver4DictBuffers,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.cpp
index ba405b07e..18f558094 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.cpp
@@ -29,6 +29,8 @@ const int FormatUtils::DICTIONARY_MINIMUM_SIZE = 12;
     switch (formatVersion) {
         case VERSION_2:
             return VERSION_2;
+        case VERSION_401:
+            return VERSION_401;
         case VERSION_4_ONLY_FOR_TESTING:
             return VERSION_4_ONLY_FOR_TESTING;
         case VERSION_4:
@@ -60,6 +62,8 @@ const int FormatUtils::DICTIONARY_MINIMUM_SIZE = 12;
             // same so we use them for both here.
             if (ByteArrayUtils::readUint16(dict, 4) == VERSION_2) {
                 return VERSION_2;
+            } else if (ByteArrayUtils::readUint16(dict, 4) == VERSION_401) {
+                return VERSION_401;
             } else if (ByteArrayUtils::readUint16(dict, 4) == VERSION_4_ONLY_FOR_TESTING) {
                 return VERSION_4_ONLY_FOR_TESTING;
             } else if (ByteArrayUtils::readUint16(dict, 4) == VERSION_4) {
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.h b/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.h
index c47f30ca4..b05cb2fc8 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/format_utils.h
@@ -32,8 +32,9 @@ class FormatUtils {
         // These MUST have the same values as the relevant constants in FormatSpec.java.
         VERSION_2 = 2,
         VERSION_4_ONLY_FOR_TESTING = 399,
-        VERSION_4 = 401,
-        VERSION_4_DEV = 402,
+        VERSION_401 = 401,
+        VERSION_4 = 402,
+        VERSION_4_DEV = 403,
         UNKNOWN_VERSION = -1
     };
 
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
index d551cc7e6..3349a3247 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
@@ -64,7 +64,7 @@ public class BinaryDictionaryDecayingTests extends AndroidTestCase {
     }
 
     private static boolean supportsBeginningOfSentence(final int formatVersion) {
-        return formatVersion >= FormatSpec.VERSION4_DEV;
+        return formatVersion > FormatSpec.VERSION401;
     }
 
     private void addUnigramWord(final BinaryDictionary binaryDictionary, final String word,
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
index 31ad3446a..79384092a 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -47,11 +47,11 @@ public class BinaryDictionaryTests extends AndroidTestCase {
             new int[] { FormatSpec.VERSION4, FormatSpec.VERSION4_DEV };
 
     private static boolean canCheckBigramProbability(final int formatVersion) {
-        return formatVersion >= FormatSpec.VERSION4_DEV;
+        return formatVersion > FormatSpec.VERSION401;
     }
 
     private static boolean supportsBeginningOfSentence(final int formatVersion) {
-        return formatVersion >= FormatSpec.VERSION4_DEV;
+        return formatVersion > FormatSpec.VERSION401;
     }
 
     private File createEmptyDictionaryAndGetFile(final String dictId,