diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 121fd53..a351ee9 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -41,7 +41,6 @@
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Locale;
-import java.util.Map;
 
 /**
  * Implements a static, compacted, binary dictionary of standard words.
@@ -124,7 +123,8 @@
     }
 
     /**
-     * Constructs binary dictionary using existing dictionary file.
+     * Constructor for the binary dictionary. This is supposed to be called from the
+     * dictionary factory.
      * @param filename the name of the file to read through native code.
      * @param offset the offset of the dictionary data within the file.
      * @param length the length of the binary data.
@@ -145,38 +145,6 @@
         loadDictionary(filename, offset, length, isUpdatable);
     }
 
-    /**
-     * Constructs binary dictionary on memory.
-     * @param filename the name of the file used to flush.
-     * @param useFullEditDistance whether to use the full edit distance in suggestions
-     * @param dictType the dictionary type, as a human-readable string
-     * @param formatVersion the format version of the dictionary
-     * @param attributeMap the attributes of the dictionary
-     */
-    @UsedForTesting
-    public BinaryDictionary(final String filename, final boolean useFullEditDistance,
-            final Locale locale, final String dictType, final long formatVersion,
-            final Map<String, String> attributeMap) {
-        super(dictType);
-        mLocale = locale;
-        mDictSize = 0;
-        mDictFilePath = filename;
-        // On memory dictionary is always updatable.
-        mIsUpdatable = true;
-        mHasUpdated = false;
-        mNativeSuggestOptions.setUseFullEditDistance(useFullEditDistance);
-        final String[] keyArray = new String[attributeMap.size()];
-        final String[] valueArray = new String[attributeMap.size()];
-        int index = 0;
-        for (final String key : attributeMap.keySet()) {
-            keyArray[index] = key;
-            valueArray[index] = attributeMap.get(key);
-            index++;
-        }
-        mNativeDict = openOnMemoryNative(formatVersion, locale.toString(), keyArray, valueArray);
-    }
-
-
     static {
         JniUtils.loadNativeLibrary();
     }
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 251a719..ab943a3 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/header/header_policy.h
@@ -99,27 +99,6 @@
               mMaxBigramCount(HeaderReadWriteUtils::readIntAttributeValue(
                       &mAttributeMap, MAX_BIGRAM_COUNT_KEY, DEFAULT_MAX_BIGRAM_COUNT)) {}
 
-    // Copy header information
-    HeaderPolicy(const HeaderPolicy *const headerPolicy)
-            : mDictFormatVersion(headerPolicy->mDictFormatVersion),
-              mDictionaryFlags(headerPolicy->mDictionaryFlags), mSize(headerPolicy->mSize),
-              mAttributeMap(headerPolicy->mAttributeMap), mLocale(headerPolicy->mLocale),
-              mMultiWordCostMultiplier(headerPolicy->mMultiWordCostMultiplier),
-              mRequiresGermanUmlautProcessing(headerPolicy->mRequiresGermanUmlautProcessing),
-              mIsDecayingDict(headerPolicy->mIsDecayingDict),
-              mDate(headerPolicy->mDate), mLastDecayedTime(headerPolicy->mLastDecayedTime),
-              mUnigramCount(headerPolicy->mUnigramCount), mBigramCount(headerPolicy->mBigramCount),
-              mExtendedRegionSize(headerPolicy->mExtendedRegionSize),
-              mHasHistoricalInfoOfWords(headerPolicy->mHasHistoricalInfoOfWords),
-              mForgettingCurveOccurrencesToLevelUp(
-                      headerPolicy->mForgettingCurveOccurrencesToLevelUp),
-              mForgettingCurveProbabilityValuesTableId(
-                      headerPolicy->mForgettingCurveProbabilityValuesTableId),
-              mForgettingCurveDurationToLevelDown(
-                      headerPolicy->mForgettingCurveDurationToLevelDown),
-              mMaxUnigramCount(headerPolicy->mMaxUnigramCount),
-              mMaxBigramCount(headerPolicy->mMaxBigramCount) {}
-
     // Temporary dummy header.
     HeaderPolicy()
             : mDictFormatVersion(FormatUtils::UNKNOWN_VERSION), mDictionaryFlags(0), mSize(0),
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 be7e43b..eefedc3 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
@@ -19,12 +19,10 @@
 #include <climits>
 
 #include "defines.h"
-#include "suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_writing_utils.h"
 #include "suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h"
-#include "suggest/policyimpl/dictionary/utils/dict_file_writing_utils.h"
 #include "suggest/policyimpl/dictionary/utils/file_utils.h"
 #include "suggest/policyimpl/dictionary/utils/format_utils.h"
 #include "suggest/policyimpl/dictionary/utils/mmapped_buffer.h"
@@ -58,11 +56,6 @@
             Ver4DictBuffers::Ver4DictBuffersPtr dictBuffers =
                     Ver4DictBuffers::createVer4DictBuffers(&headerPolicy,
                             Ver4DictConstants::MAX_DICT_EXTENDED_REGION_SIZE);
-            if (!DynamicPtWritingUtils::writeEmptyDictionary(
-                    dictBuffers->getWritableTrieBuffer(), 0 /* rootPos */)) {
-                AKLOGE("Empty ver4 dictionary structure cannot be created on memory.");
-                return DictionaryStructureWithBufferPolicy::StructurePolicyPtr(nullptr);
-            }
             return DictionaryStructureWithBufferPolicy::StructurePolicyPtr(
                     new Ver4PatriciaTriePolicy(std::move(dictBuffers)));
         }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
index 95f6544..eda882d 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.cpp
@@ -131,7 +131,7 @@
           mIsUpdatable(isUpdatable) {}
 
 Ver4DictBuffers::Ver4DictBuffers(const HeaderPolicy *const headerPolicy, const int maxTrieSize)
-        : mHeaderBuffer(nullptr), mDictBuffer(nullptr), mHeaderPolicy(headerPolicy),
+        : mHeaderBuffer(nullptr), mDictBuffer(nullptr), mHeaderPolicy(),
           mExpandableHeaderBuffer(Ver4DictConstants::MAX_DICTIONARY_SIZE),
           mExpandableTrieBuffer(maxTrieSize), mTerminalPositionLookupTable(),
           mProbabilityDictContent(headerPolicy->hasHistoricalInfoOfWords()),
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
index 0fb0fa5..b476627 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -97,37 +97,6 @@
         binaryDictionary.close();
     }
 
-    public void testConstructingDictionaryOnMemory() {
-        testConstructingDictionaryOnMemory(FormatSpec.VERSION4);
-    }
-
-    private void testConstructingDictionaryOnMemory(final int formatVersion) {
-        File dictFile = null;
-        try {
-            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary", formatVersion);
-        } catch (IOException e) {
-            fail("IOException while writing an initial dictionary : " + e);
-        }
-        FileUtils.deleteRecursively(dictFile);
-        assertFalse(dictFile.exists());
-        BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
-                true /* useFullEditDistance */, Locale.getDefault(), TEST_LOCALE, formatVersion,
-                new HashMap<String, String>());
-        assertTrue(binaryDictionary.isValidDictionary());
-        assertEquals(formatVersion, binaryDictionary.getFormatVersion());
-        final int probability = 100;
-        addUnigramWord(binaryDictionary, "word", probability);
-        assertEquals(probability, binaryDictionary.getFrequency("word"));
-        assertFalse(dictFile.exists());
-        binaryDictionary.flush();
-        assertTrue(dictFile.exists());
-        assertTrue(binaryDictionary.isValidDictionary());
-        assertEquals(formatVersion, binaryDictionary.getFormatVersion());
-        assertEquals(probability, binaryDictionary.getFrequency("word"));
-        binaryDictionary.close();
-        dictFile.delete();
-    }
-
     public void testAddTooLongWord() {
         testAddTooLongWord(FormatSpec.VERSION4);
     }