diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
index 609b8ab..9af5a37 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
@@ -57,6 +57,9 @@
     virtual bool writePtNodeAndAdvancePosition(const PtNodeParams *const ptNodeParams,
             int *const ptNodeWritingPos) = 0;
 
+    virtual bool writeNewTerminalPtNodeAndAdvancePosition(const PtNodeParams *const ptNodeParams,
+            int *const ptNodeWritingPos) = 0;
+
     virtual bool addNewBigramEntry(const PtNodeParams *const sourcePtNodeParams,
             const PtNodeParams *const targetPtNodeParam, const int probability,
             bool *const outAddedNewBigram) = 0;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.cpp
index 36b2049..aa200b2 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.cpp
@@ -23,6 +23,7 @@
 #include "suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_reading_utils.h"
 #include "suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_utils.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/forgetting_curve_utils.h"
 
 namespace latinime {
 
@@ -105,9 +106,11 @@
     if (!toBeUpdatedPtNodeParams->isTerminal()) {
         return false;
     }
+    const int probabilityToWrite = getUpdatedProbability(toBeUpdatedPtNodeParams->getProbability(),
+            newProbability);
     int probabilityFieldPos = toBeUpdatedPtNodeParams->getProbabilityFieldPos();
     return DynamicPatriciaTrieWritingUtils::writeProbabilityAndAdvancePosition(mBuffer,
-            newProbability, &probabilityFieldPos);
+            probabilityToWrite, &probabilityFieldPos);
 }
 
 bool DynamicPatriciaTrieNodeWriter::updateChildrenPosition(
@@ -119,67 +122,24 @@
 
 bool DynamicPatriciaTrieNodeWriter::writePtNodeAndAdvancePosition(
         const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos) {
-    const int nodePos = *ptNodeWritingPos;
-    // Write dummy flags. The Node flags are updated with appropriate flags at the last step of the
-    // PtNode writing.
-    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mBuffer,
-            0 /* nodeFlags */, ptNodeWritingPos)) {
+    return writePtNodeAndGetProbabilityFieldPosAndAdvancePosition(ptNodeParams,
+            0 /* outProbabilityFieldPos */, ptNodeWritingPos);
+}
+
+bool DynamicPatriciaTrieNodeWriter::writeNewTerminalPtNodeAndAdvancePosition(
+        const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos) {
+    int probabilityFieldPos = NOT_A_DICT_POS;
+    if (!writePtNodeAndGetProbabilityFieldPosAndAdvancePosition(ptNodeParams, &probabilityFieldPos,
+            ptNodeWritingPos)) {
         return false;
     }
-    // Calculate a parent offset and write the offset.
-    if (!DynamicPatriciaTrieWritingUtils::writeParentPosOffsetAndAdvancePosition(mBuffer,
-            ptNodeParams->getParentPos(), nodePos, ptNodeWritingPos)) {
+    if (probabilityFieldPos == NOT_A_DICT_POS) {
         return false;
     }
-    // Write code points
-    if (!DynamicPatriciaTrieWritingUtils::writeCodePointsAndAdvancePosition(mBuffer,
-            ptNodeParams->getCodePoints(), ptNodeParams->getCodePointCount(), ptNodeWritingPos)) {
-        return false;
-    }
-    // Write probability when the probability is a valid probability, which means this node is
-    // terminal.
-    if (ptNodeParams->getProbability() != NOT_A_PROBABILITY) {
-        if (!DynamicPatriciaTrieWritingUtils::writeProbabilityAndAdvancePosition(mBuffer,
-                ptNodeParams->getProbability(), ptNodeWritingPos)) {
-            return false;
-        }
-    }
-    // Write children position
-    if (!DynamicPatriciaTrieWritingUtils::writeChildrenPositionAndAdvancePosition(mBuffer,
-            ptNodeParams->getChildrenPos(), ptNodeWritingPos)) {
-        return false;
-    }
-    // Copy shortcut list when the originalShortcutListPos is valid dictionary position.
-    if (ptNodeParams->getShortcutPos() != NOT_A_DICT_POS) {
-        int fromPos = ptNodeParams->getShortcutPos();
-        if (!mShortcutPolicy->copyAllShortcutsAndReturnIfSucceededOrNot(mBuffer, &fromPos,
-                ptNodeWritingPos)) {
-            return false;
-        }
-    }
-    // Copy bigram list when the originalBigramListPos is valid dictionary position.
-    int bigramCount = 0;
-    if (ptNodeParams->getBigramsPos() != NOT_A_DICT_POS) {
-        int fromPos = ptNodeParams->getBigramsPos();
-        if (!mBigramPolicy->copyAllBigrams(mBuffer, &fromPos, ptNodeWritingPos, &bigramCount)) {
-            return false;
-        }
-    }
-    // Create node flags and write them.
-    PatriciaTrieReadingUtils::NodeFlags nodeFlags =
-            PatriciaTrieReadingUtils::createAndGetFlags(ptNodeParams->isBlacklisted(),
-                    ptNodeParams->isNotAWord(),
-                    ptNodeParams->getProbability() != NOT_A_PROBABILITY /* isTerminal */,
-                    ptNodeParams->getShortcutPos() != NOT_A_DICT_POS /* hasShortcutTargets */,
-                    bigramCount > 0 /* hasBigrams */,
-                    ptNodeParams->getCodePointCount() > 1 /* hasMultipleChars */,
-                    CHILDREN_POSITION_FIELD_SIZE);
-    int flagsFieldPos = nodePos;
-    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mBuffer, nodeFlags,
-            &flagsFieldPos)) {
-        return false;
-    }
-    return true;
+    const int probabilityToWrite = getUpdatedProbability(
+            NOT_A_PROBABILITY /* originalProbability */, ptNodeParams->getProbability());
+    return DynamicPatriciaTrieWritingUtils::writeProbabilityAndAdvancePosition(mBuffer,
+            probabilityToWrite, &probabilityFieldPos);
 }
 
 bool DynamicPatriciaTrieNodeWriter::addNewBigramEntry(
@@ -289,4 +249,90 @@
     return true;
 }
 
+bool DynamicPatriciaTrieNodeWriter::writePtNodeAndGetProbabilityFieldPosAndAdvancePosition(
+        const PtNodeParams *const ptNodeParams, int *const outProbabilityFieldPos,
+        int *const ptNodeWritingPos) {
+    const int nodePos = *ptNodeWritingPos;
+    // Write dummy flags. The Node flags are updated with appropriate flags at the last step of the
+    // PtNode writing.
+    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mBuffer,
+            0 /* nodeFlags */, ptNodeWritingPos)) {
+        return false;
+    }
+    // Calculate a parent offset and write the offset.
+    if (!DynamicPatriciaTrieWritingUtils::writeParentPosOffsetAndAdvancePosition(mBuffer,
+            ptNodeParams->getParentPos(), nodePos, ptNodeWritingPos)) {
+        return false;
+    }
+    // Write code points
+    if (!DynamicPatriciaTrieWritingUtils::writeCodePointsAndAdvancePosition(mBuffer,
+            ptNodeParams->getCodePoints(), ptNodeParams->getCodePointCount(), ptNodeWritingPos)) {
+        return false;
+    }
+    // Write probability when the probability is a valid probability, which means this node is
+    // terminal.
+    if (ptNodeParams->isTerminal()) {
+        if (outProbabilityFieldPos) {
+            *outProbabilityFieldPos = *ptNodeWritingPos;
+        }
+        if (ptNodeParams->getProbability() == NOT_A_PROBABILITY) {
+            // Write a dummy probability.
+            if (!DynamicPatriciaTrieWritingUtils::writeProbabilityAndAdvancePosition(mBuffer,
+                    0 /* probability */, ptNodeWritingPos)) {
+                return false;
+            }
+        } else {
+            if (!DynamicPatriciaTrieWritingUtils::writeProbabilityAndAdvancePosition(mBuffer,
+                    ptNodeParams->getProbability(), ptNodeWritingPos)) {
+                return false;
+            }
+        }
+    }
+    // Write children position
+    if (!DynamicPatriciaTrieWritingUtils::writeChildrenPositionAndAdvancePosition(mBuffer,
+            ptNodeParams->getChildrenPos(), ptNodeWritingPos)) {
+        return false;
+    }
+    // Copy shortcut list when the originalShortcutListPos is valid dictionary position.
+    if (ptNodeParams->getShortcutPos() != NOT_A_DICT_POS) {
+        int fromPos = ptNodeParams->getShortcutPos();
+        if (!mShortcutPolicy->copyAllShortcutsAndReturnIfSucceededOrNot(mBuffer, &fromPos,
+                ptNodeWritingPos)) {
+            return false;
+        }
+    }
+    // Copy bigram list when the originalBigramListPos is valid dictionary position.
+    int bigramCount = 0;
+    if (ptNodeParams->getBigramsPos() != NOT_A_DICT_POS) {
+        int fromPos = ptNodeParams->getBigramsPos();
+        if (!mBigramPolicy->copyAllBigrams(mBuffer, &fromPos, ptNodeWritingPos, &bigramCount)) {
+            return false;
+        }
+    }
+    // Create node flags and write them.
+    PatriciaTrieReadingUtils::NodeFlags nodeFlags =
+            PatriciaTrieReadingUtils::createAndGetFlags(ptNodeParams->isBlacklisted(),
+                    ptNodeParams->isNotAWord(), ptNodeParams->isTerminal(),
+                    ptNodeParams->getShortcutPos() != NOT_A_DICT_POS /* hasShortcutTargets */,
+                    bigramCount > 0 /* hasBigrams */,
+                    ptNodeParams->getCodePointCount() > 1 /* hasMultipleChars */,
+                    CHILDREN_POSITION_FIELD_SIZE);
+    int flagsFieldPos = nodePos;
+    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mBuffer, nodeFlags,
+            &flagsFieldPos)) {
+        return false;
+    }
+    return true;
+}
+
+int DynamicPatriciaTrieNodeWriter::getUpdatedProbability(const int originalProbability,
+        const int newProbability) const {
+    if (mNeedsToDecayWhenUpdating) {
+        return ForgettingCurveUtils::getUpdatedEncodedProbability(originalProbability,
+                newProbability);
+    } else {
+        return newProbability;
+    }
+}
+
 }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.h
index e1d08fb..20b0ca4 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_node_writer.h
@@ -39,9 +39,10 @@
     DynamicPatriciaTrieNodeWriter(BufferWithExtendableBuffer *const buffer,
             const DynamicPatriciaTrieNodeReader *const ptNodeReader,
             DynamicBigramListPolicy *const bigramPolicy,
-            DynamicShortcutListPolicy *const shortcutPolicy)
+            DynamicShortcutListPolicy *const shortcutPolicy, const bool needsToDecayWhenUpdating)
             : mBuffer(buffer), mPtNodeReader(ptNodeReader), mReadingHelper(mBuffer, ptNodeReader),
-              mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy) {}
+              mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy),
+              mNeedsToDecayWhenUpdating(needsToDecayWhenUpdating) {}
 
     virtual ~DynamicPatriciaTrieNodeWriter() {}
 
@@ -59,6 +60,9 @@
     virtual bool writePtNodeAndAdvancePosition(const PtNodeParams *const ptNodeParams,
             int *const ptNodeWritingPos);
 
+    virtual bool writeNewTerminalPtNodeAndAdvancePosition(
+            const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos);
+
     virtual bool addNewBigramEntry(const PtNodeParams *const sourcePtNodeParams,
             const PtNodeParams *const targetPtNodeParam, const int probability,
             bool *const outAddedNewBigram);
@@ -76,6 +80,12 @@
  private:
     DISALLOW_COPY_AND_ASSIGN(DynamicPatriciaTrieNodeWriter);
 
+    bool writePtNodeAndGetProbabilityFieldPosAndAdvancePosition(
+            const PtNodeParams *const ptNodeParams, int *const outProbabilityFieldPos,
+            int *const ptNodeWritingPos);
+
+    int getUpdatedProbability(const int originalProbability, const int newProbability) const;
+
     static const int CHILDREN_POSITION_FIELD_SIZE;
 
     BufferWithExtendableBuffer *const mBuffer;
@@ -83,7 +93,7 @@
     DynamicPatriciaTrieReadingHelper mReadingHelper;
     DynamicBigramListPolicy *const mBigramPolicy;
     DynamicShortcutListPolicy *const mShortcutPolicy;
-
+    const bool mNeedsToDecayWhenUpdating;
 };
 } // namespace latinime
 #endif /* LATINIME_DYNAMIC_PATRICIA_TRIE_NODE_WRITER_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.cpp
index d4fb937..e80c758 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.cpp
@@ -231,8 +231,8 @@
         AKLOGI("Warning: flush() is called for non-updatable dictionary.");
         return;
     }
-    DynamicPatriciaTrieWritingHelper writingHelper(&mBufferWithExtendableBuffer, &mNodeReader,
-            &mNodeWriter, &mBigramListPolicy, &mShortcutListPolicy, false /* needsToDecay */);
+    DynamicPatriciaTrieWritingHelper writingHelper(&mBufferWithExtendableBuffer,
+            &mBigramListPolicy, &mShortcutListPolicy, false /* needsToDecay */);
     writingHelper.writeToDictFile(filePath, &mHeaderPolicy, mUnigramCount, mBigramCount);
 }
 
@@ -246,8 +246,8 @@
                     false /* mindsBlockByDecay */, mUnigramCount, mBigramCount, &mHeaderPolicy));
     DynamicBigramListPolicy bigramListPolicyForGC(&mHeaderPolicy, &mBufferWithExtendableBuffer,
             &mShortcutListPolicy, needsToDecay);
-    DynamicPatriciaTrieWritingHelper writingHelper(&mBufferWithExtendableBuffer, &mNodeReader,
-            &mNodeWriter, &bigramListPolicyForGC, &mShortcutListPolicy, needsToDecay);
+    DynamicPatriciaTrieWritingHelper writingHelper(&mBufferWithExtendableBuffer,
+            &bigramListPolicyForGC, &mShortcutListPolicy, needsToDecay);
     writingHelper.writeToDictFileWithGC(getRootPosition(), filePath, &mHeaderPolicy);
     mNeedsToDecayForTesting = false;
 }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.h
index 636c9bf..fec9efc 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_policy.h
@@ -49,9 +49,8 @@
                       mHeaderPolicy.isDecayingDict()),
               mNodeReader(&mBufferWithExtendableBuffer, &mBigramListPolicy, &mShortcutListPolicy),
               mNodeWriter(&mBufferWithExtendableBuffer, &mNodeReader, &mBigramListPolicy,
-                      &mShortcutListPolicy),
-              mUpdatingHelper(&mBufferWithExtendableBuffer, &mNodeReader, &mNodeWriter,
-                      mHeaderPolicy.isDecayingDict()),
+                      &mShortcutListPolicy, mHeaderPolicy.isDecayingDict()),
+              mUpdatingHelper(&mBufferWithExtendableBuffer, &mNodeReader, &mNodeWriter),
               mUnigramCount(mHeaderPolicy.getUnigramCount()),
               mBigramCount(mHeaderPolicy.getBigramCount()), mNeedsToDecayForTesting(false) {}
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.cpp
index 39e1eca..e70c0ec 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.cpp
@@ -22,7 +22,6 @@
 #include "suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_reading_helper.h"
 #include "suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_utils.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
-#include "suggest/policyimpl/dictionary/utils/forgetting_curve_utils.h"
 
 namespace latinime {
 
@@ -53,9 +52,7 @@
             if (nextIndex >= codePointCount || !readingHelper->isMatchedCodePoint(ptNodeParams, j,
                     wordCodePoints[matchedCodePointCount + j])) {
                 *outAddedNewUnigram = true;
-                return reallocatePtNodeAndAddNewPtNodes(&ptNodeParams, j,
-                        getUpdatedProbability(NOT_A_PROBABILITY /* originalProbability */,
-                                probability),
+                return reallocatePtNodeAndAddNewPtNodes(&ptNodeParams, j, probability,
                         wordCodePoints + matchedCodePointCount,
                         codePointCount - matchedCodePointCount);
             }
@@ -66,8 +63,7 @@
         }
         if (!ptNodeParams.hasChildren()) {
             *outAddedNewUnigram = true;
-            return createChildrenPtNodeArrayAndAChildPtNode(&ptNodeParams,
-                    getUpdatedProbability(NOT_A_PROBABILITY /* originalProbability */, probability),
+            return createChildrenPtNodeArrayAndAChildPtNode(&ptNodeParams, probability,
                     wordCodePoints + readingHelper->getTotalCodePointCount(ptNodeParams),
                     codePointCount - readingHelper->getTotalCodePointCount(ptNodeParams));
         }
@@ -83,8 +79,7 @@
     *outAddedNewUnigram = true;
     return createAndInsertNodeIntoPtNodeArray(parentPos,
             wordCodePoints + readingHelper->getPrevTotalCodePointCount(),
-            codePointCount - readingHelper->getPrevTotalCodePointCount(),
-            getUpdatedProbability(NOT_A_PROBABILITY /* originalProbability */, probability), &pos);
+            codePointCount - readingHelper->getPrevTotalCodePointCount(), probability, &pos);
 }
 
 bool DynamicPatriciaTrieUpdatingHelper::addBigramWords(const int word0Pos, const int word1Pos,
@@ -124,19 +119,18 @@
     if (originalPtNodeParams->isTerminal()) {
         // Overwrites the probability.
         *outAddedNewUnigram = false;
-        const int probabilityToWrite = getUpdatedProbability(
-                originalPtNodeParams->getProbability(), probability);
-        return mPtNodeWriter->updatePtNodeProbability(originalPtNodeParams, probabilityToWrite);
+        return mPtNodeWriter->updatePtNodeProbability(originalPtNodeParams, probability);
     } else {
         // Make the node terminal and write the probability.
         *outAddedNewUnigram = true;
         const int movedPos = mBuffer->getTailPosition();
         int writingPos = movedPos;
         const PtNodeParams ptNodeParamsToWrite(getUpdatedPtNodeParams(originalPtNodeParams,
-                originalPtNodeParams->getParentPos(), originalPtNodeParams->getCodePointCount(),
-                originalPtNodeParams->getCodePoints(),
-                getUpdatedProbability(NOT_A_PROBABILITY /* originalProbability */, probability)));
-        if (!mPtNodeWriter->writePtNodeAndAdvancePosition(&ptNodeParamsToWrite, &writingPos)) {
+                true /* isTerminal */, originalPtNodeParams->getParentPos(),
+                originalPtNodeParams->getCodePointCount(), originalPtNodeParams->getCodePoints(),
+                probability));
+        if (!mPtNodeWriter->writeNewTerminalPtNodeAndAdvancePosition(&ptNodeParamsToWrite,
+                &writingPos)) {
             return false;
         }
         if (!mPtNodeWriter->markPtNodeAsMoved(originalPtNodeParams, movedPos, movedPos)) {
@@ -165,9 +159,10 @@
             1 /* arraySize */, &writingPos)) {
         return false;
     }
-    const PtNodeParams ptNodeParamsToWrite(getPtNodeParamsForNewPtNode(
+    const PtNodeParams ptNodeParamsToWrite(getPtNodeParamsForNewPtNode(true /* isTerminal */,
             parentPtNodePos, nodeCodePointCount, nodeCodePoints, probability));
-    if (!mPtNodeWriter->writePtNodeAndAdvancePosition(&ptNodeParamsToWrite, &writingPos)) {
+    if (!mPtNodeWriter->writeNewTerminalPtNodeAndAdvancePosition(&ptNodeParamsToWrite,
+            &writingPos)) {
         return false;
     }
     if (!DynamicPatriciaTrieWritingUtils::writeForwardLinkPositionAndAdvancePosition(mBuffer,
@@ -194,12 +189,21 @@
     int writingPos = firstPartOfReallocatedPtNodePos;
     // Write the 1st part of the reallocating node. The children position will be updated later
     // with actual children position.
-    const int newProbability = addsExtraChild ? NOT_A_PROBABILITY : probabilityOfNewPtNode;
-    const PtNodeParams ptNodeParamsToWrite(getPtNodeParamsForNewPtNode(
-            reallocatingPtNodeParams->getParentPos(), overlappingCodePointCount,
-            reallocatingPtNodeParams->getCodePoints(), newProbability));
-    if (!mPtNodeWriter->writePtNodeAndAdvancePosition(&ptNodeParamsToWrite, &writingPos)) {
-        return false;
+    if (addsExtraChild) {
+        const PtNodeParams ptNodeParamsToWrite(getPtNodeParamsForNewPtNode(false /* isTerminal */,
+                reallocatingPtNodeParams->getParentPos(), overlappingCodePointCount,
+                reallocatingPtNodeParams->getCodePoints(), NOT_A_PROBABILITY));
+        if (!mPtNodeWriter->writePtNodeAndAdvancePosition(&ptNodeParamsToWrite, &writingPos)) {
+            return false;
+        }
+    } else {
+        const PtNodeParams ptNodeParamsToWrite(getPtNodeParamsForNewPtNode(true /* isTerminal */,
+                reallocatingPtNodeParams->getParentPos(), overlappingCodePointCount,
+                reallocatingPtNodeParams->getCodePoints(), probabilityOfNewPtNode));
+        if (!mPtNodeWriter->writeNewTerminalPtNodeAndAdvancePosition(&ptNodeParamsToWrite,
+                &writingPos)) {
+            return false;
+        }
     }
     const int actualChildrenPos = writingPos;
     // Create new children PtNode array.
@@ -211,7 +215,7 @@
     // Write the 2nd part of the reallocating node.
     const int secondPartOfReallocatedPtNodePos = writingPos;
     const PtNodeParams childPartPtNodeParams(getUpdatedPtNodeParams(reallocatingPtNodeParams,
-            firstPartOfReallocatedPtNodePos,
+            reallocatingPtNodeParams->isTerminal(), firstPartOfReallocatedPtNodePos,
             reallocatingPtNodeParams->getCodePointCount() - overlappingCodePointCount,
             reallocatingPtNodeParams->getCodePoints() + overlappingCodePointCount,
             reallocatingPtNodeParams->getProbability()));
@@ -219,10 +223,11 @@
         return false;
     }
     if (addsExtraChild) {
-        const PtNodeParams extraChildPtNodeParams(getPtNodeParamsForNewPtNode(
+        const PtNodeParams extraChildPtNodeParams(getPtNodeParamsForNewPtNode(true /* isTerminal */,
                 firstPartOfReallocatedPtNodePos, newNodeCodePointCount - overlappingCodePointCount,
                 newNodeCodePoints + overlappingCodePointCount, probabilityOfNewPtNode));
-        if (!mPtNodeWriter->writePtNodeAndAdvancePosition(&extraChildPtNodeParams, &writingPos)) {
+        if (!mPtNodeWriter->writeNewTerminalPtNodeAndAdvancePosition(&extraChildPtNodeParams,
+                &writingPos)) {
             return false;
         }
     }
@@ -242,22 +247,11 @@
     return mPtNodeWriter->updateChildrenPosition(&ptNodeParams, actualChildrenPos);
 }
 
-int DynamicPatriciaTrieUpdatingHelper::getUpdatedProbability(const int originalProbability,
-        const int newProbability) const {
-    if (mNeedsToDecay) {
-        return ForgettingCurveUtils::getUpdatedEncodedProbability(originalProbability,
-                newProbability);
-    } else {
-        return newProbability;
-    }
-}
-
 const PtNodeParams DynamicPatriciaTrieUpdatingHelper::getUpdatedPtNodeParams(
-        const PtNodeParams *const originalPtNodeParams, const int parentPos,
+        const PtNodeParams *const originalPtNodeParams, const bool isTerminal, const int parentPos,
         const int codePointCount, const int *const codePoints, const int probability) const {
     const PatriciaTrieReadingUtils::NodeFlags flags = PatriciaTrieReadingUtils::createAndGetFlags(
-            originalPtNodeParams->isBlacklisted(), originalPtNodeParams->isNotAWord(),
-            probability != NOT_A_PROBABILITY /* isTerminal */,
+            originalPtNodeParams->isBlacklisted(), originalPtNodeParams->isNotAWord(), isTerminal,
             originalPtNodeParams->hasShortcutTargets(), originalPtNodeParams->hasBigrams(),
             codePointCount > 1 /* hasMultipleChars */, CHILDREN_POSITION_FIELD_SIZE);
     return PtNodeParams(originalPtNodeParams, flags, parentPos, codePointCount, codePoints,
@@ -265,11 +259,10 @@
 }
 
 const PtNodeParams DynamicPatriciaTrieUpdatingHelper::getPtNodeParamsForNewPtNode(
-        const int parentPos, const int codePointCount, const int *const codePoints,
-        const int probability) const {
+        const bool isTerminal, const int parentPos, const int codePointCount,
+        const int *const codePoints, const int probability) const {
     const PatriciaTrieReadingUtils::NodeFlags flags = PatriciaTrieReadingUtils::createAndGetFlags(
-            false /* isBlacklisted */, false /* isNotAWord */,
-            probability != NOT_A_PROBABILITY /* isTerminal */,
+            false /* isBlacklisted */, false /* isNotAWord */, isTerminal,
             false /* hasShortcutTargets */, false /* hasBigrams */,
             codePointCount > 1 /* hasMultipleChars */, CHILDREN_POSITION_FIELD_SIZE);
     return PtNodeParams(flags, parentPos, codePointCount, codePoints, probability);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.h
index b9800cd..cc51d4b 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_updating_helper.h
@@ -34,10 +34,8 @@
 class DynamicPatriciaTrieUpdatingHelper {
  public:
     DynamicPatriciaTrieUpdatingHelper(BufferWithExtendableBuffer *const buffer,
-            const PtNodeReader *const ptNodeReader, PtNodeWriter *const ptNodeWriter,
-            const bool needsToDecay)
-            : mBuffer(buffer), mPtNodeReader(ptNodeReader), mPtNodeWriter(ptNodeWriter),
-              mNeedsToDecay(needsToDecay) {}
+            const PtNodeReader *const ptNodeReader, PtNodeWriter *const ptNodeWriter)
+            : mBuffer(buffer), mPtNodeReader(ptNodeReader), mPtNodeWriter(ptNodeWriter) {}
 
     ~DynamicPatriciaTrieUpdatingHelper() {}
 
@@ -61,7 +59,6 @@
     BufferWithExtendableBuffer *const mBuffer;
     const PtNodeReader *const mPtNodeReader;
     PtNodeWriter *const mPtNodeWriter;
-    const bool mNeedsToDecay;
 
     bool createAndInsertNodeIntoPtNodeArray(const int parentPos, const int *const nodeCodePoints,
             const int nodeCodePointCount, const int probability, int *const forwardLinkFieldPos);
@@ -80,14 +77,12 @@
             const int probabilityOfNewPtNode, const int *const newNodeCodePoints,
             const int newNodeCodePointCount);
 
-    int getUpdatedProbability(const int originalProbability, const int newProbability) const;
-
     const PtNodeParams getUpdatedPtNodeParams(const PtNodeParams *const originalPtNodeParams,
-            const int parentPos, const int codePointCount, const int *const codePoints,
-            const int probability) const;
-
-    const PtNodeParams getPtNodeParamsForNewPtNode(const int parentPos, const int codePointCount,
+            const bool isTerminal, const int parentPos, const int codePointCount,
             const int *const codePoints, const int probability) const;
+
+    const PtNodeParams getPtNodeParamsForNewPtNode(const bool isTerminal, const int parentPos,
+            const int codePointCount, const int *const codePoints, const int probability) const;
 };
 } // namespace latinime
 #endif /* LATINIME_DYNAMIC_PATRICIA_TRIE_UPDATING_HELPER_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.cpp
index fe5e2c6..321189d 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.cpp
@@ -76,11 +76,13 @@
         int *const outUnigramCount, int *const outBigramCount) {
     DynamicPatriciaTrieNodeReader ptNodeReader(mBuffer, mBigramPolicy, mShortcutPolicy);
     DynamicPatriciaTrieReadingHelper readingHelper(mBuffer, &ptNodeReader);
+    DynamicPatriciaTrieNodeWriter ptNodeWriter(mBuffer, &ptNodeReader, mBigramPolicy,
+            mShortcutPolicy, false /* needsToDecayWhenUpdating */);
     readingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
     DynamicPatriciaTrieGcEventListeners
             ::TraversePolicyToUpdateUnigramProbabilityAndMarkUselessPtNodesAsDeleted
                     traversePolicyToUpdateUnigramProbabilityAndMarkUselessPtNodesAsDeleted(
-                            headerPolicy, mPtNodeWriter, mBuffer, mNeedsToDecay);
+                            headerPolicy, &ptNodeWriter, mBuffer, mNeedsToDecay);
     if (!readingHelper.traverseAllPtNodesInPostorderDepthFirstManner(
             &traversePolicyToUpdateUnigramProbabilityAndMarkUselessPtNodesAsDeleted)) {
         return false;
@@ -92,7 +94,7 @@
 
     readingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
     DynamicPatriciaTrieGcEventListeners::TraversePolicyToUpdateBigramProbability
-            traversePolicyToUpdateBigramProbability(mPtNodeWriter);
+            traversePolicyToUpdateBigramProbability(&ptNodeWriter);
     if (!readingHelper.traverseAllPtNodesInPostorderDepthFirstManner(
             &traversePolicyToUpdateBigramProbability)) {
         return false;
@@ -106,7 +108,7 @@
     PtNodeWriter::DictPositionRelocationMap dictPositionRelocationMap;
     readingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
     DynamicPatriciaTrieNodeWriter newPtNodeWriter(bufferToWrite, &ptNodeReader, mBigramPolicy,
-            mShortcutPolicy);
+            mShortcutPolicy, false /* needsToDecayWhenUpdating */);
     DynamicPatriciaTrieGcEventListeners::TraversePolicyToPlaceAndWriteValidPtNodesToBuffer
             traversePolicyToPlaceAndWriteValidPtNodesToBuffer(&newPtNodeWriter, bufferToWrite,
                     &dictPositionRelocationMap);
@@ -124,7 +126,7 @@
             &newDictShortcutPolicy);
     DynamicPatriciaTrieReadingHelper newDictReadingHelper(bufferToWrite, &newDictNodeReader);
     DynamicPatriciaTrieNodeWriter newDictNodeWriter(bufferToWrite, &newDictNodeReader,
-            &newDictBigramPolicy, &newDictShortcutPolicy);
+            &newDictBigramPolicy, &newDictShortcutPolicy, false /* needsToDecayWhenUpdating */);
     newDictReadingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
     DynamicPatriciaTrieGcEventListeners::TraversePolicyToUpdateAllPositionFields
             traversePolicyToUpdateAllPositionFields(&newDictNodeWriter, &dictPositionRelocationMap);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.h
index e343bf9..6d722e5 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_helper.h
@@ -29,8 +29,6 @@
 class DynamicPatriciaTrieReadingHelper;
 class DynamicShortcutListPolicy;
 class HeaderPolicy;
-class PtNodeReader;
-class PtNodeWriter;
 
 // TODO: Make it independent from a particular format and move to pt_common.
 class DynamicPatriciaTrieWritingHelper {
@@ -38,11 +36,9 @@
     static const size_t MAX_DICTIONARY_SIZE;
 
     DynamicPatriciaTrieWritingHelper(BufferWithExtendableBuffer *const buffer,
-            const PtNodeReader *const ptNodeReader, PtNodeWriter *const ptNodeWriter,
             DynamicBigramListPolicy *const bigramPolicy,
             DynamicShortcutListPolicy *const shortcutPolicy, const bool needsToDecay)
-            : mBuffer(buffer), mPtNodeReader(ptNodeReader), mPtNodeWriter(ptNodeWriter),
-              mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy),
+            : mBuffer(buffer), mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy),
               mNeedsToDecay(needsToDecay) {}
 
     ~DynamicPatriciaTrieWritingHelper() {}
@@ -57,8 +53,6 @@
     DISALLOW_IMPLICIT_CONSTRUCTORS(DynamicPatriciaTrieWritingHelper);
 
     BufferWithExtendableBuffer *const mBuffer;
-    const PtNodeReader *const mPtNodeReader;
-    PtNodeWriter *const mPtNodeWriter;
     DynamicBigramListPolicy *const mBigramPolicy;
     DynamicShortcutListPolicy *const mShortcutPolicy;
     const bool mNeedsToDecay;
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 e8a3142..2775457 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
@@ -24,6 +24,7 @@
 #include "suggest/policyimpl/dictionary/structure/v3/dynamic_patricia_trie_writing_utils.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
+#include "suggest/policyimpl/dictionary/utils/forgetting_curve_utils.h"
 
 namespace latinime {
 
@@ -115,8 +116,10 @@
     if (!toBeUpdatedPtNodeParams->isTerminal()) {
         return false;
     }
+    const int probabilityToWrite = getUpdatedProbability(toBeUpdatedPtNodeParams->getProbability(),
+            newProbability);
     return mBuffers->getUpdatableProbabilityDictContent()->setProbability(
-            toBeUpdatedPtNodeParams->getTerminalId(), newProbability);
+            toBeUpdatedPtNodeParams->getTerminalId(), probabilityToWrite);
 }
 
 bool Ver4PatriciaTrieNodeWriter::updateChildrenPosition(
@@ -134,67 +137,23 @@
 
 bool Ver4PatriciaTrieNodeWriter::writePtNodeAndAdvancePosition(
         const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos) {
-    const int nodePos = *ptNodeWritingPos;
-    // Write dummy flags. The Node flags are updated with appropriate flags at the last step of the
-    // PtNode writing.
-    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mTrieBuffer,
-            0 /* nodeFlags */, ptNodeWritingPos)) {
-        return false;
-    }
-    // Calculate a parent offset and write the offset.
-    if (!DynamicPatriciaTrieWritingUtils::writeParentPosOffsetAndAdvancePosition(mTrieBuffer,
-            ptNodeParams->getParentPos(), nodePos, ptNodeWritingPos)) {
-        return false;
-    }
-    // Write code points
-    if (!DynamicPatriciaTrieWritingUtils::writeCodePointsAndAdvancePosition(mTrieBuffer,
-            ptNodeParams->getCodePoints(), ptNodeParams->getCodePointCount(), ptNodeWritingPos)) {
-        return false;
-    }
+    return writePtNodeAndGetTerminalIdAndAdvancePosition(ptNodeParams, 0 /* outTerminalId */,
+            ptNodeWritingPos);
+}
+
+
+bool Ver4PatriciaTrieNodeWriter::writeNewTerminalPtNodeAndAdvancePosition(
+        const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos) {
     int terminalId = Ver4DictConstants::NOT_A_TERMINAL_ID;
-    if (ptNodeParams->getTerminalId() != Ver4DictConstants::NOT_A_TERMINAL_ID) {
-        terminalId = ptNodeParams->getTerminalId();
-    } else if (ptNodeParams->getProbability() != NOT_A_PROBABILITY) {
-        // Write terminal information using a new terminal id.
-        // Get a new unused terminal id.
-        terminalId = mBuffers->getTerminalPositionLookupTable()->getNextTerminalId();
-    }
-    const int isTerminal = terminalId != Ver4DictConstants::NOT_A_TERMINAL_ID;
-    if (isTerminal) {
-        // Update the lookup table.
-        if (!mBuffers->getUpdatableTerminalPositionLookupTable()->setTerminalPtNodePosition(
-                terminalId, nodePos)) {
-            return false;
-        }
-        // Write terminal Id.
-        if (!mTrieBuffer->writeUintAndAdvancePosition(terminalId,
-                Ver4DictConstants::TERMINAL_ID_FIELD_SIZE, ptNodeWritingPos)) {
-            return false;
-        }
-        // Write probability.
-        if (!mBuffers->getUpdatableProbabilityDictContent()->setProbability(
-                terminalId, ptNodeParams->getProbability())) {
-            return false;
-        }
-    }
-    // Write children position
-    if (!DynamicPatriciaTrieWritingUtils::writeChildrenPositionAndAdvancePosition(mTrieBuffer,
-            ptNodeParams->getChildrenPos(), ptNodeWritingPos)) {
+    if (!writePtNodeAndGetTerminalIdAndAdvancePosition(ptNodeParams, &terminalId,
+            ptNodeWritingPos)) {
         return false;
     }
-    // Create node flags and write them.
-    PatriciaTrieReadingUtils::NodeFlags nodeFlags =
-            PatriciaTrieReadingUtils::createAndGetFlags(ptNodeParams->isBlacklisted(),
-                    ptNodeParams->isNotAWord(), isTerminal,
-                    ptNodeParams->hasShortcutTargets(), ptNodeParams->hasBigrams(),
-                    ptNodeParams->getCodePointCount() > 1 /* hasMultipleChars */,
-                    CHILDREN_POSITION_FIELD_SIZE);
-    int flagsFieldPos = nodePos;
-    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mTrieBuffer, nodeFlags,
-            &flagsFieldPos)) {
-        return false;
-    }
-    return true;
+    // Write probability.
+    const int probabilityToWrite = getUpdatedProbability(NOT_A_PROBABILITY,
+            ptNodeParams->getProbability());
+    return mBuffers->getUpdatableProbabilityDictContent()->setProbability(terminalId,
+            probabilityToWrite);
 }
 
 bool Ver4PatriciaTrieNodeWriter::addNewBigramEntry(
@@ -258,4 +217,85 @@
     return true;
 }
 
+bool Ver4PatriciaTrieNodeWriter::writePtNodeAndGetTerminalIdAndAdvancePosition(
+        const PtNodeParams *const ptNodeParams, int *const outTerminalId,
+        int *const ptNodeWritingPos) {
+    const int nodePos = *ptNodeWritingPos;
+    // Write dummy flags. The Node flags are updated with appropriate flags at the last step of the
+    // PtNode writing.
+    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mTrieBuffer,
+            0 /* nodeFlags */, ptNodeWritingPos)) {
+        return false;
+    }
+    // Calculate a parent offset and write the offset.
+    if (!DynamicPatriciaTrieWritingUtils::writeParentPosOffsetAndAdvancePosition(mTrieBuffer,
+            ptNodeParams->getParentPos(), nodePos, ptNodeWritingPos)) {
+        return false;
+    }
+    // Write code points
+    if (!DynamicPatriciaTrieWritingUtils::writeCodePointsAndAdvancePosition(mTrieBuffer,
+            ptNodeParams->getCodePoints(), ptNodeParams->getCodePointCount(), ptNodeWritingPos)) {
+        return false;
+    }
+    int terminalId = Ver4DictConstants::NOT_A_TERMINAL_ID;
+    if (ptNodeParams->getTerminalId() != Ver4DictConstants::NOT_A_TERMINAL_ID) {
+        terminalId = ptNodeParams->getTerminalId();
+    } else if (ptNodeParams->isTerminal()) {
+        // Write terminal information using a new terminal id.
+        // Get a new unused terminal id.
+        terminalId = mBuffers->getTerminalPositionLookupTable()->getNextTerminalId();
+    }
+    const int isTerminal = terminalId != Ver4DictConstants::NOT_A_TERMINAL_ID;
+    if (isTerminal) {
+        // Update the lookup table.
+        if (!mBuffers->getUpdatableTerminalPositionLookupTable()->setTerminalPtNodePosition(
+                terminalId, nodePos)) {
+            return false;
+        }
+        // Write terminal Id.
+        if (!mTrieBuffer->writeUintAndAdvancePosition(terminalId,
+                Ver4DictConstants::TERMINAL_ID_FIELD_SIZE, ptNodeWritingPos)) {
+            return false;
+        }
+        // Write probability.
+        if (ptNodeParams->getProbability() != NOT_A_PROBABILITY) {
+            if (!mBuffers->getUpdatableProbabilityDictContent()->setProbability(
+                    terminalId, ptNodeParams->getProbability())) {
+                return false;
+            }
+        }
+        if (outTerminalId) {
+            *outTerminalId = terminalId;
+        }
+    }
+    // Write children position
+    if (!DynamicPatriciaTrieWritingUtils::writeChildrenPositionAndAdvancePosition(mTrieBuffer,
+            ptNodeParams->getChildrenPos(), ptNodeWritingPos)) {
+        return false;
+    }
+    // Create node flags and write them.
+    PatriciaTrieReadingUtils::NodeFlags nodeFlags =
+            PatriciaTrieReadingUtils::createAndGetFlags(ptNodeParams->isBlacklisted(),
+                    ptNodeParams->isNotAWord(), isTerminal,
+                    ptNodeParams->hasShortcutTargets(), ptNodeParams->hasBigrams(),
+                    ptNodeParams->getCodePointCount() > 1 /* hasMultipleChars */,
+                    CHILDREN_POSITION_FIELD_SIZE);
+    int flagsFieldPos = nodePos;
+    if (!DynamicPatriciaTrieWritingUtils::writeFlagsAndAdvancePosition(mTrieBuffer, nodeFlags,
+            &flagsFieldPos)) {
+        return false;
+    }
+    return true;
+}
+
+int Ver4PatriciaTrieNodeWriter::getUpdatedProbability(const int originalProbability,
+        const int newProbability) const {
+    if (mNeedsToDecayWhenUpdating) {
+        return ForgettingCurveUtils::getUpdatedEncodedProbability(originalProbability,
+                newProbability);
+    } else {
+        return newProbability;
+    }
+}
+
 }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
index 1245152..2d83635 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
@@ -39,10 +39,12 @@
  public:
     Ver4PatriciaTrieNodeWriter(BufferWithExtendableBuffer *const trieBuffer,
             Ver4DictBuffers *const buffers, const Ver4PatriciaTrieNodeReader *const ptNodeReader,
-            Ver4BigramListPolicy *const bigramPolicy, Ver4ShortcutListPolicy *const shortcutPolicy)
+            Ver4BigramListPolicy *const bigramPolicy, Ver4ShortcutListPolicy *const shortcutPolicy,
+            const bool needsToDecayWhenUpdating)
             : mTrieBuffer(trieBuffer), mBuffers(buffers), mPtNodeReader(ptNodeReader),
               mReadingHelper(mTrieBuffer, mPtNodeReader),
-              mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy) {}
+              mBigramPolicy(bigramPolicy), mShortcutPolicy(shortcutPolicy),
+              mNeedsToDecayWhenUpdating(needsToDecayWhenUpdating) {}
 
     virtual ~Ver4PatriciaTrieNodeWriter() {}
 
@@ -63,6 +65,9 @@
     virtual bool writePtNodeAndAdvancePosition(const PtNodeParams *const ptNodeParams,
             int *const ptNodeWritingPos);
 
+    virtual bool writeNewTerminalPtNodeAndAdvancePosition(
+            const PtNodeParams *const ptNodeParams, int *const ptNodeWritingPos);
+
     virtual bool addNewBigramEntry(const PtNodeParams *const sourcePtNodeParams,
             const PtNodeParams *const targetPtNodeParam, const int probability,
             bool *const outAddedNewBigram);
@@ -80,6 +85,12 @@
  private:
     DISALLOW_COPY_AND_ASSIGN(Ver4PatriciaTrieNodeWriter);
 
+    bool writePtNodeAndGetTerminalIdAndAdvancePosition(
+            const PtNodeParams *const ptNodeParams, int *const outTerminalId,
+            int *const ptNodeWritingPos);
+
+    int getUpdatedProbability(const int originalProbability, const int newProbability) const;
+
     static const int CHILDREN_POSITION_FIELD_SIZE;
 
     BufferWithExtendableBuffer *const mTrieBuffer;
@@ -88,6 +99,7 @@
     DynamicPatriciaTrieReadingHelper mReadingHelper;
     Ver4BigramListPolicy *const mBigramPolicy;
     Ver4ShortcutListPolicy *const mShortcutPolicy;
+    const bool mNeedsToDecayWhenUpdating;
 };
 } // namespace latinime
 #endif /* LATINIME_VER4_PATRICIA_TRIE_NODE_WRITER_H */
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
index 3606a2a..f2ce529 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
@@ -49,9 +49,8 @@
                       mBuffers.get()->getTerminalPositionLookupTable()),
               mNodeReader(mDictBuffer, mBuffers.get()->getProbabilityDictContent()),
               mNodeWriter(mDictBuffer, mBuffers.get(), &mNodeReader, &mBigramPolicy,
-                      &mShortcutPolicy),
-              mUpdatingHelper(mDictBuffer, &mNodeReader, &mNodeWriter,
-                      mHeaderPolicy.isDecayingDict()),
+                      &mShortcutPolicy, mHeaderPolicy.isDecayingDict()),
+              mUpdatingHelper(mDictBuffer, &mNodeReader, &mNodeWriter),
               mWritingHelper(mBuffers.get()),
               mUnigramCount(mHeaderPolicy.getUnigramCount()),
               mBigramCount(mHeaderPolicy.getBigramCount()), mNeedsToDecayForTesting(false) {};
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
index ea03c72..a7b729b 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
@@ -87,7 +87,8 @@
     Ver4ShortcutListPolicy shortcutPolicy(mBuffers->getShortcutDictContent(),
             mBuffers->getTerminalPositionLookupTable());
     Ver4PatriciaTrieNodeWriter ptNodeWriter(mBuffers->getWritableTrieBuffer(),
-            mBuffers, &ptNodeReader, &bigramPolicy, &shortcutPolicy);
+            mBuffers, &ptNodeReader, &bigramPolicy, &shortcutPolicy,
+            false /* needsToDecayWhenUpdating */);
 
     DynamicPatriciaTrieReadingHelper readingHelper(mBuffers->getTrieBuffer(), &ptNodeReader);
     readingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
@@ -121,7 +122,8 @@
     PtNodeWriter::DictPositionRelocationMap dictPositionRelocationMap;
     readingHelper.initWithPtNodeArrayPos(rootPtNodeArrayPos);
     Ver4PatriciaTrieNodeWriter ptNodeWriterForNewBuffers(buffersToWrite->getWritableTrieBuffer(),
-            buffersToWrite, &ptNodeReader, &bigramPolicy, &shortcutPolicy);
+            buffersToWrite, &ptNodeReader, &bigramPolicy, &shortcutPolicy,
+            false /* needsToDecayWhenUpdating */);
     DynamicPatriciaTrieGcEventListeners::TraversePolicyToPlaceAndWriteValidPtNodesToBuffer
             traversePolicyToPlaceAndWriteValidPtNodesToBuffer(&ptNodeWriterForNewBuffers,
                     buffersToWrite->getWritableTrieBuffer(), &dictPositionRelocationMap);
@@ -139,7 +141,8 @@
     Ver4ShortcutListPolicy newShortcutPolicy(buffersToWrite->getShortcutDictContent(),
             buffersToWrite->getTerminalPositionLookupTable());
     Ver4PatriciaTrieNodeWriter newPtNodeWriter(buffersToWrite->getWritableTrieBuffer(),
-            buffersToWrite, &newPtNodeReader, &newBigramPolicy, &newShortcutPolicy);
+            buffersToWrite, &newPtNodeReader, &newBigramPolicy, &newShortcutPolicy,
+            false /* needsToDecayWhenUpdating */);
 
     DynamicPatriciaTrieReadingHelper newDictReadingHelper(buffersToWrite->getTrieBuffer(),
             &newPtNodeReader);