diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_entry.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_entry.h
index ed77bd2..3dfaba7 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_entry.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/probability_entry.h
@@ -43,14 +43,13 @@
             : mFlags(flags), mProbability(probability), mHistoricalInfo() {}
 
     // Entry with historical information.
-    ProbabilityEntry(const int flags, const int probability,
-            const HistoricalInfo *const historicalInfo)
-            : mFlags(flags), mProbability(probability), mHistoricalInfo(*historicalInfo) {}
+    ProbabilityEntry(const int flags, const HistoricalInfo *const historicalInfo)
+            : mFlags(flags), mProbability(NOT_A_PROBABILITY), mHistoricalInfo(*historicalInfo) {}
 
     // Create from unigram property.
-    // TODO: Set flags.
     ProbabilityEntry(const UnigramProperty *const unigramProperty)
-            : mFlags(0), mProbability(unigramProperty->getProbability()),
+            : mFlags(createFlags(unigramProperty->representsBeginningOfSentence())),
+              mProbability(unigramProperty->getProbability()),
               mHistoricalInfo(unigramProperty->getTimestamp(), unigramProperty->getLevel(),
                       unigramProperty->getCount()) {}
 
@@ -61,15 +60,6 @@
               mHistoricalInfo(bigramProperty->getTimestamp(), bigramProperty->getLevel(),
                       bigramProperty->getCount()) {}
 
-    const ProbabilityEntry createEntryWithUpdatedProbability(const int probability) const {
-        return ProbabilityEntry(mFlags, probability, &mHistoricalInfo);
-    }
-
-    const ProbabilityEntry createEntryWithUpdatedHistoricalInfo(
-            const HistoricalInfo *const historicalInfo) const {
-        return ProbabilityEntry(mFlags, mProbability, historicalInfo);
-    }
-
     bool isValid() const {
         return (mProbability != NOT_A_PROBABILITY) || hasHistoricalInfo();
     }
@@ -78,7 +68,7 @@
         return mHistoricalInfo.isValid();
     }
 
-    int getFlags() const {
+    uint8_t getFlags() const {
         return mFlags;
     }
 
@@ -90,6 +80,10 @@
         return &mHistoricalInfo;
     }
 
+    bool representsBeginningOfSentence() const {
+        return (mFlags & Ver4DictConstants::FLAG_REPRESENTS_BEGINNING_OF_SENTENCE) != 0;
+    }
+
     uint64_t encode(const bool hasHistoricalInfo) const {
         uint64_t encodedEntry = static_cast<uint64_t>(mFlags);
         if (hasHistoricalInfo) {
@@ -123,7 +117,7 @@
             const int count = readFromEncodedEntry(encodedEntry,
                     Ver4DictConstants::WORD_COUNT_FIELD_SIZE, 0 /* pos */);
             const HistoricalInfo historicalInfo(timestamp, level, count);
-            return ProbabilityEntry(flags, NOT_A_PROBABILITY, &historicalInfo);
+            return ProbabilityEntry(flags, &historicalInfo);
         } else {
             const int flags = readFromEncodedEntry(encodedEntry,
                     Ver4DictConstants::FLAGS_IN_LANGUAGE_MODEL_SIZE,
@@ -138,7 +132,7 @@
     // Copy constructor is public to use this class as a type of return value.
     DISALLOW_ASSIGNMENT_OPERATOR(ProbabilityEntry);
 
-    const int mFlags;
+    const uint8_t mFlags;
     const int mProbability;
     const HistoricalInfo mHistoricalInfo;
 
@@ -146,6 +140,14 @@
         return static_cast<int>(
                 (encodedEntry >> (pos * CHAR_BIT)) & ((1ull << (size * CHAR_BIT)) - 1));
     }
+
+    static uint8_t createFlags(const bool representsBeginningOfSentence) {
+        uint8_t flags = 0;
+        if (representsBeginningOfSentence) {
+            flags ^= Ver4DictConstants::FLAG_REPRESENTS_BEGINNING_OF_SENTENCE;
+        }
+        return flags;
+    }
 };
 } // namespace latinime
 #endif /* LATINIME_PROBABILITY_ENTRY_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
index e622442..b085a66 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.cpp
@@ -54,6 +54,8 @@
 const int Ver4DictConstants::WORD_LEVEL_FIELD_SIZE = 1;
 const int Ver4DictConstants::WORD_COUNT_FIELD_SIZE = 1;
 
+const uint8_t Ver4DictConstants::FLAG_REPRESENTS_BEGINNING_OF_SENTENCE = 0x1;
+
 const int Ver4DictConstants::BIGRAM_ADDRESS_TABLE_BLOCK_SIZE = 16;
 const int Ver4DictConstants::BIGRAM_ADDRESS_TABLE_DATA_SIZE = 4;
 const int Ver4DictConstants::SHORTCUT_ADDRESS_TABLE_BLOCK_SIZE = 64;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
index 8d29f60..230b305 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h
@@ -20,6 +20,7 @@
 #include "defines.h"
 
 #include <cstddef>
+#include <cstdint>
 
 namespace latinime {
 
@@ -48,6 +49,8 @@
     static const int TIME_STAMP_FIELD_SIZE;
     static const int WORD_LEVEL_FIELD_SIZE;
     static const int WORD_COUNT_FIELD_SIZE;
+    // Flags in probability entry.
+    static const uint8_t FLAG_REPRESENTS_BEGINNING_OF_SENTENCE;
 
     static const int BIGRAM_ADDRESS_TABLE_BLOCK_SIZE;
     static const int BIGRAM_ADDRESS_TABLE_DATA_SIZE;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
index 62e008b..fb6840b 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
@@ -164,8 +164,8 @@
     if (originalProbabilityEntry.hasHistoricalInfo()) {
         const HistoricalInfo historicalInfo = ForgettingCurveUtils::createHistoricalInfoToSave(
                 originalProbabilityEntry.getHistoricalInfo(), mHeaderPolicy);
-        const ProbabilityEntry probabilityEntry =
-                originalProbabilityEntry.createEntryWithUpdatedHistoricalInfo(&historicalInfo);
+        const ProbabilityEntry probabilityEntry(originalProbabilityEntry.getFlags(),
+                &historicalInfo);
         if (!mBuffers->getMutableLanguageModelDictContent()->setProbabilityEntry(
                 toBeUpdatedPtNodeParams->getTerminalId(), &probabilityEntry)) {
             AKLOGE("Cannot write updated probability entry. terminalId: %d",
@@ -383,18 +383,15 @@
 const ProbabilityEntry Ver4PatriciaTrieNodeWriter::createUpdatedEntryFrom(
         const ProbabilityEntry *const originalProbabilityEntry,
         const ProbabilityEntry *const probabilityEntry) const {
-    // TODO: Consolidate historical info and probability.
     if (mHeaderPolicy->hasHistoricalInfoOfWords()) {
         const HistoricalInfo updatedHistoricalInfo =
                 ForgettingCurveUtils::createUpdatedHistoricalInfo(
                         originalProbabilityEntry->getHistoricalInfo(),
                         probabilityEntry->getProbability(), probabilityEntry->getHistoricalInfo(),
                         mHeaderPolicy);
-        return originalProbabilityEntry->createEntryWithUpdatedHistoricalInfo(
-                &updatedHistoricalInfo);
+        return ProbabilityEntry(probabilityEntry->getFlags(), &updatedHistoricalInfo);
     } else {
-        return originalProbabilityEntry->createEntryWithUpdatedProbability(
-                probabilityEntry->getProbability());
+        return *probabilityEntry;
     }
 }
 
diff --git a/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content_test.cpp b/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content_test.cpp
index a1a3b1a..3cacba1 100644
--- a/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content_test.cpp
+++ b/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content_test.cpp
@@ -53,7 +53,7 @@
     const int count = 10;
     const int wordId = 100;
     const HistoricalInfo historicalInfo(timestamp, level, count);
-    const ProbabilityEntry probabilityEntry(flag, NOT_A_PROBABILITY, &historicalInfo);
+    const ProbabilityEntry probabilityEntry(flag, &historicalInfo);
     LanguageModelDictContent.setProbabilityEntry(wordId, &probabilityEntry);
     const ProbabilityEntry entry = LanguageModelDictContent.getProbabilityEntry(wordId);
     EXPECT_EQ(flag, entry.getFlags());
diff --git a/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/probability_entry_test.cpp b/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/probability_entry_test.cpp
index db94550..f0494f3 100644
--- a/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/probability_entry_test.cpp
+++ b/native/jni/tests/suggest/policyimpl/dictionary/structure/v4/content/probability_entry_test.cpp
@@ -43,7 +43,7 @@
     const int count = 10;
 
     const HistoricalInfo historicalInfo(timestamp, level, count);
-    const ProbabilityEntry entry(flag, NOT_A_PROBABILITY, &historicalInfo);
+    const ProbabilityEntry entry(flag, &historicalInfo);
 
     const uint64_t encodedEntry = entry.encode(true /* hasHistoricalInfo */);
     EXPECT_EQ(0xF03FFFFFFF030Aull, encodedEntry);