diff --git a/java/res/values/keyboard-themes.xml b/java/res/values/keyboard-themes.xml
index 9d772c4..b0bae96 100644
--- a/java/res/values/keyboard-themes.xml
+++ b/java/res/values/keyboard-themes.xml
@@ -26,10 +26,10 @@
         <item>@string/keyboard_theme_holo_blue</item>
     </string-array>
     <!-- An element must be a keyboard theme id of {@link KeyboardTheme#THEME_ID_*}. -->
-    <string-array name="keyboard_theme_ids" translatable="false">
+    <integer-array name="keyboard_theme_ids" translatable="false">
         <item>3</item>
         <item>4</item>
         <item>2</item>
         <item>0</item>
-    </string-array>
+    </integer-array>
 </resources>
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardSwitcher.java b/java/src/com/android/inputmethod/keyboard/KeyboardSwitcher.java
index d36c199..6cd7955 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardSwitcher.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardSwitcher.java
@@ -17,9 +17,7 @@
 package com.android.inputmethod.keyboard;
 
 import android.content.Context;
-import android.content.SharedPreferences;
 import android.content.res.Resources;
-import android.preference.PreferenceManager;
 import android.util.Log;
 import android.view.ContextThemeWrapper;
 import android.view.LayoutInflater;
@@ -47,7 +45,6 @@
     private static final String TAG = KeyboardSwitcher.class.getSimpleName();
 
     private SubtypeSwitcher mSubtypeSwitcher;
-    private SharedPreferences mPrefs;
 
     private InputView mCurrentInputView;
     private View mMainKeyboardFrame;
@@ -76,13 +73,11 @@
     }
 
     public static void init(final LatinIME latinIme) {
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(latinIme);
-        sInstance.initInternal(latinIme, prefs);
+        sInstance.initInternal(latinIme);
     }
 
-    private void initInternal(final LatinIME latinIme, final SharedPreferences prefs) {
+    private void initInternal(final LatinIME latinIme) {
         mLatinIME = latinIme;
-        mPrefs = prefs;
         mSubtypeSwitcher = SubtypeSwitcher.getInstance();
         mState = new KeyboardState(this);
         mIsHardwareAcceleratedDrawingEnabled =
@@ -91,7 +86,7 @@
 
     public void updateKeyboardTheme() {
         final boolean themeUpdated = updateKeyboardThemeAndContextThemeWrapper(
-                mLatinIME, KeyboardTheme.getKeyboardTheme(mPrefs));
+                mLatinIME, KeyboardTheme.getKeyboardTheme(mLatinIME /* context */));
         if (themeUpdated && mKeyboardView != null) {
             mLatinIME.setInputView(onCreateInputView(mIsHardwareAcceleratedDrawingEnabled));
         }
@@ -348,7 +343,7 @@
         }
 
         updateKeyboardThemeAndContextThemeWrapper(
-                mLatinIME, KeyboardTheme.getKeyboardTheme(mPrefs));
+                mLatinIME, KeyboardTheme.getKeyboardTheme(mLatinIME /* context */));
         mCurrentInputView = (InputView)LayoutInflater.from(mThemeContext).inflate(
                 R.layout.input_view, null);
         mMainKeyboardFrame = mCurrentInputView.findViewById(R.id.main_keyboard_frame);
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardTheme.java b/java/src/com/android/inputmethod/keyboard/KeyboardTheme.java
index 7161d3f..6d8c8b7 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardTheme.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardTheme.java
@@ -16,14 +16,17 @@
 
 package com.android.inputmethod.keyboard;
 
+import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Build.VERSION_CODES;
+import android.preference.PreferenceManager;
 import android.util.Log;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.compat.BuildCompatUtils;
 import com.android.inputmethod.latin.R;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 
 public final class KeyboardTheme implements Comparable<KeyboardTheme> {
@@ -40,7 +43,10 @@
     public static final int THEME_ID_LXX_DARK = 4;
     public static final int DEFAULT_THEME_ID = THEME_ID_KLP;
 
-    private static final KeyboardTheme[] KEYBOARD_THEMES = {
+    private static KeyboardTheme[] AVAILABLE_KEYBOARD_THEMES;
+
+    @UsedForTesting
+    static final KeyboardTheme[] KEYBOARD_THEMES = {
         new KeyboardTheme(THEME_ID_ICS, "ICS", R.style.KeyboardTheme_ICS,
                 // This has never been selected because we support ICS or later.
                 VERSION_CODES.BASE),
@@ -93,9 +99,10 @@
     }
 
     @UsedForTesting
-    static KeyboardTheme searchKeyboardThemeById(final int themeId) {
+    static KeyboardTheme searchKeyboardThemeById(final int themeId,
+            final KeyboardTheme[] availableThemeIds) {
         // TODO: This search algorithm isn't optimal if there are many themes.
-        for (final KeyboardTheme theme : KEYBOARD_THEMES) {
+        for (final KeyboardTheme theme : availableThemeIds) {
             if (theme.mThemeId == themeId) {
                 return theme;
             }
@@ -105,13 +112,14 @@
 
     @UsedForTesting
     static KeyboardTheme getDefaultKeyboardTheme(final SharedPreferences prefs,
-            final int sdkVersion) {
+            final int sdkVersion, final KeyboardTheme[] availableThemeArray) {
         final String klpThemeIdString = prefs.getString(KLP_KEYBOARD_THEME_KEY, null);
         if (klpThemeIdString != null) {
             if (sdkVersion <= VERSION_CODES.KITKAT) {
                 try {
                     final int themeId = Integer.parseInt(klpThemeIdString);
-                    final KeyboardTheme theme = searchKeyboardThemeById(themeId);
+                    final KeyboardTheme theme = searchKeyboardThemeById(themeId,
+                            availableThemeArray);
                     if (theme != null) {
                         return theme;
                     }
@@ -125,22 +133,21 @@
             prefs.edit().remove(KLP_KEYBOARD_THEME_KEY).apply();
         }
         // TODO: This search algorithm isn't optimal if there are many themes.
-        for (final KeyboardTheme theme : KEYBOARD_THEMES) {
+        for (final KeyboardTheme theme : availableThemeArray) {
             if (sdkVersion >= theme.mMinApiVersion) {
                 return theme;
             }
         }
-        return searchKeyboardThemeById(DEFAULT_THEME_ID);
+        return searchKeyboardThemeById(DEFAULT_THEME_ID, availableThemeArray);
     }
 
     public static String getKeyboardThemeName(final int themeId) {
-        final KeyboardTheme theme = searchKeyboardThemeById(themeId);
+        final KeyboardTheme theme = searchKeyboardThemeById(themeId, KEYBOARD_THEMES);
         return theme.mThemeName;
     }
 
-    public static void saveKeyboardThemeId(final String themeIdString,
-            final SharedPreferences prefs) {
-        saveKeyboardThemeId(themeIdString, prefs, BuildCompatUtils.EFFECTIVE_SDK_INT);
+    public static void saveKeyboardThemeId(final int themeId, final SharedPreferences prefs) {
+        saveKeyboardThemeId(themeId, prefs, BuildCompatUtils.EFFECTIVE_SDK_INT);
     }
 
     @UsedForTesting
@@ -152,25 +159,45 @@
     }
 
     @UsedForTesting
-    static void saveKeyboardThemeId(final String themeIdString,
-            final SharedPreferences prefs, final int sdkVersion) {
+    static void saveKeyboardThemeId(final int themeId, final SharedPreferences prefs,
+            final int sdkVersion) {
         final String prefKey = getPreferenceKey(sdkVersion);
-        prefs.edit().putString(prefKey, themeIdString).apply();
+        prefs.edit().putString(prefKey, Integer.toString(themeId)).apply();
     }
 
-    public static KeyboardTheme getKeyboardTheme(final SharedPreferences prefs) {
-        return getKeyboardTheme(prefs, BuildCompatUtils.EFFECTIVE_SDK_INT);
+    public static KeyboardTheme getKeyboardTheme(final Context context) {
+        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        final KeyboardTheme[] availableThemeArray = getAvailableThemeArray(context);
+        return getKeyboardTheme(prefs, BuildCompatUtils.EFFECTIVE_SDK_INT, availableThemeArray);
+    }
+
+    static KeyboardTheme[] getAvailableThemeArray(final Context context) {
+        if (AVAILABLE_KEYBOARD_THEMES == null) {
+            final int[] availableThemeIdStringArray = context.getResources().getIntArray(
+                    R.array.keyboard_theme_ids);
+            final ArrayList<KeyboardTheme> availableThemeList = new ArrayList<>();
+            for (final int id : availableThemeIdStringArray) {
+                final KeyboardTheme theme = searchKeyboardThemeById(id, KEYBOARD_THEMES);
+                if (theme != null) {
+                    availableThemeList.add(theme);
+                }
+            }
+            AVAILABLE_KEYBOARD_THEMES = availableThemeList.toArray(
+                    new KeyboardTheme[availableThemeList.size()]);
+        }
+        return AVAILABLE_KEYBOARD_THEMES;
     }
 
     @UsedForTesting
-    static KeyboardTheme getKeyboardTheme(final SharedPreferences prefs, final int sdkVersion) {
+    static KeyboardTheme getKeyboardTheme(final SharedPreferences prefs, final int sdkVersion,
+            final KeyboardTheme[] availableThemeArray) {
         final String lxxThemeIdString = prefs.getString(LXX_KEYBOARD_THEME_KEY, null);
         if (lxxThemeIdString == null) {
-            return getDefaultKeyboardTheme(prefs, sdkVersion);
+            return getDefaultKeyboardTheme(prefs, sdkVersion, availableThemeArray);
         }
         try {
             final int themeId = Integer.parseInt(lxxThemeIdString);
-            final KeyboardTheme theme = searchKeyboardThemeById(themeId);
+            final KeyboardTheme theme = searchKeyboardThemeById(themeId, availableThemeArray);
             if (theme != null) {
                 return theme;
             }
@@ -180,6 +207,6 @@
         }
         // Remove preference that contains unknown or illegal theme id.
         prefs.edit().remove(LXX_KEYBOARD_THEME_KEY).apply();
-        return getDefaultKeyboardTheme(prefs, sdkVersion);
+        return getDefaultKeyboardTheme(prefs, sdkVersion, availableThemeArray);
     }
 }
diff --git a/java/src/com/android/inputmethod/latin/settings/ThemeSettingsFragment.java b/java/src/com/android/inputmethod/latin/settings/ThemeSettingsFragment.java
index 5a3fc36..29289ae 100644
--- a/java/src/com/android/inputmethod/latin/settings/ThemeSettingsFragment.java
+++ b/java/src/com/android/inputmethod/latin/settings/ThemeSettingsFragment.java
@@ -17,7 +17,6 @@
 package com.android.inputmethod.latin.settings;
 
 import android.content.Context;
-import android.content.SharedPreferences;
 import android.content.res.Resources;
 import android.os.Bundle;
 import android.preference.Preference;
@@ -32,12 +31,12 @@
  */
 public final class ThemeSettingsFragment extends SubScreenFragment
         implements OnRadioButtonClickedListener {
-    private String mSelectedThemeId;
+    private int mSelectedThemeId;
 
     static class KeyboardThemePreference extends RadioButtonPreference {
-        final String mThemeId;
+        final int mThemeId;
 
-        KeyboardThemePreference(final Context context, final String name, final String id) {
+        KeyboardThemePreference(final Context context, final String name, final int id) {
             super(context);
             setTitle(name);
             mThemeId = id;
@@ -45,14 +44,13 @@
     }
 
     static void updateKeyboardThemeSummary(final Preference pref) {
-        final Resources res = pref.getContext().getResources();
-        final SharedPreferences prefs = pref.getSharedPreferences();
-        final KeyboardTheme keyboardTheme = KeyboardTheme.getKeyboardTheme(prefs);
-        final String keyboardThemeId = String.valueOf(keyboardTheme.mThemeId);
+        final Context context = pref.getContext();
+        final Resources res = context.getResources();
+        final KeyboardTheme keyboardTheme = KeyboardTheme.getKeyboardTheme(context);
         final String[] keyboardThemeNames = res.getStringArray(R.array.keyboard_theme_names);
-        final String[] keyboardThemeIds = res.getStringArray(R.array.keyboard_theme_ids);
+        final int[] keyboardThemeIds = res.getIntArray(R.array.keyboard_theme_ids);
         for (int index = 0; index < keyboardThemeNames.length; index++) {
-            if (keyboardThemeId.equals(keyboardThemeIds[index])) {
+            if (keyboardTheme.mThemeId == keyboardThemeIds[index]) {
                 pref.setSummary(keyboardThemeNames[index]);
                 return;
             }
@@ -64,18 +62,18 @@
         super.onCreate(icicle);
         addPreferencesFromResource(R.xml.prefs_screen_theme);
         final PreferenceScreen screen = getPreferenceScreen();
+        final Context context = getActivity();
         final Resources res = getResources();
         final String[] keyboardThemeNames = res.getStringArray(R.array.keyboard_theme_names);
-        final String[] keyboardThemeIds = res.getStringArray(R.array.keyboard_theme_ids);
+        final int[] keyboardThemeIds = res.getIntArray(R.array.keyboard_theme_ids);
         for (int index = 0; index < keyboardThemeNames.length; index++) {
             final KeyboardThemePreference pref = new KeyboardThemePreference(
-                    getActivity(), keyboardThemeNames[index], keyboardThemeIds[index]);
+                    context, keyboardThemeNames[index], keyboardThemeIds[index]);
             screen.addPreference(pref);
             pref.setOnRadioButtonClickedListener(this);
         }
-        final SharedPreferences prefs = getSharedPreferences();
-        final KeyboardTheme keyboardTheme = KeyboardTheme.getKeyboardTheme(prefs);
-        mSelectedThemeId = String.valueOf(keyboardTheme.mThemeId);
+        final KeyboardTheme keyboardTheme = KeyboardTheme.getKeyboardTheme(context);
+        mSelectedThemeId = keyboardTheme.mThemeId;
     }
 
     @Override
@@ -106,7 +104,7 @@
             final Preference preference = screen.getPreference(index);
             if (preference instanceof KeyboardThemePreference) {
                 final KeyboardThemePreference pref = (KeyboardThemePreference)preference;
-                final boolean selected = mSelectedThemeId.equals(pref.mThemeId);
+                final boolean selected = (mSelectedThemeId == pref.mThemeId);
                 pref.setSelected(selected);
             }
         }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
index d8ed198..ee14037 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
@@ -397,7 +397,7 @@
     WordIdArray<MAX_PREV_WORD_COUNT_FOR_N_GRAM> prevWordIdArray;
     const WordIdArrayView prevWordIds = prevWordsInfo->getPrevWordIds(this, &prevWordIdArray,
             false /* tryLowerCaseSerch */);
-    if (prevWordIds.empty() || prevWordIds[0] == NOT_A_WORD_ID) {
+    if (prevWordIds.firstOrDefault(NOT_A_WORD_ID) == NOT_A_WORD_ID) {
         return false;
     }
     const int wordPos = getTerminalPtNodePosFromWordId(getWordId(wordCodePoints,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content.cpp
index 85d6d43..35f0f76 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/content/language_model_dict_content.cpp
@@ -167,7 +167,7 @@
     if (lastBitmapEntryIndex == TrieMap::INVALID_INDEX) {
         return TrieMap::INVALID_INDEX;
     }
-    const int oldestPrevWordId = prevWordIds[prevWordIds.size() - 1];
+    const int oldestPrevWordId = prevWordIds.lastOrDefault(NOT_A_WORD_ID);
     const TrieMap::Result result = mTrieMap.get(oldestPrevWordId, lastBitmapEntryIndex);
     if (!result.mIsValid) {
         if (!mTrieMap.put(oldestPrevWordId,
@@ -175,7 +175,7 @@
             return TrieMap::INVALID_INDEX;
         }
     }
-    return mTrieMap.getNextLevelBitmapEntryIndex(prevWordIds[prevWordIds.size() - 1],
+    return mTrieMap.getNextLevelBitmapEntryIndex(prevWordIds.lastOrDefault(NOT_A_WORD_ID),
             lastBitmapEntryIndex);
 }
 
diff --git a/native/jni/src/utils/int_array_view.h b/native/jni/src/utils/int_array_view.h
index cc5f328..f3a8589 100644
--- a/native/jni/src/utils/int_array_view.h
+++ b/native/jni/src/utils/int_array_view.h
@@ -115,6 +115,20 @@
         memmove(buffer->data() + offset, mPtr, sizeof(int) * mSize);
     }
 
+    AK_FORCE_INLINE int firstOrDefault(const int defaultValue) const {
+        if (empty()) {
+            return defaultValue;
+        }
+        return mPtr[0];
+    }
+
+    AK_FORCE_INLINE int lastOrDefault(const int defaultValue) const {
+        if (empty()) {
+            return defaultValue;
+        }
+        return mPtr[mSize - 1];
+    }
+
  private:
     DISALLOW_ASSIGNMENT_OPERATOR(IntArrayView);
 
diff --git a/native/jni/tests/utils/int_array_view_test.cpp b/native/jni/tests/utils/int_array_view_test.cpp
index 934e27e..487bd04 100644
--- a/native/jni/tests/utils/int_array_view_test.cpp
+++ b/native/jni/tests/utils/int_array_view_test.cpp
@@ -124,5 +124,25 @@
     EXPECT_EQ(70, buffer[6]);
 }
 
+TEST(IntArrayViewTest, TestFirstOrDefault) {
+    const std::vector<int> intVector = {3, 2, 1, 0, -1, -2};
+    IntArrayView intArrayView(intVector);
+
+    EXPECT_EQ(3, intArrayView.firstOrDefault(10));
+    EXPECT_EQ(10, intArrayView.limit(0).firstOrDefault(10));
+    EXPECT_EQ(-10, intArrayView.limit(0).firstOrDefault(-10));
+    EXPECT_EQ(10, intArrayView.skip(6).firstOrDefault(10));
+}
+
+TEST(IntArrayViewTest, TestLastOrDefault) {
+    const std::vector<int> intVector = {3, 2, 1, 0, -1, -2};
+    IntArrayView intArrayView(intVector);
+
+    EXPECT_EQ(-2, intArrayView.lastOrDefault(10));
+    EXPECT_EQ(10, intArrayView.limit(0).lastOrDefault(10));
+    EXPECT_EQ(-10, intArrayView.limit(0).lastOrDefault(-10));
+    EXPECT_EQ(10, intArrayView.skip(6).lastOrDefault(10));
+}
+
 }  // namespace
 }  // namespace latinime
diff --git a/tests/src/com/android/inputmethod/keyboard/KeyboardLayoutSetTestsBase.java b/tests/src/com/android/inputmethod/keyboard/KeyboardLayoutSetTestsBase.java
index 5708657..b64ab8c 100644
--- a/tests/src/com/android/inputmethod/keyboard/KeyboardLayoutSetTestsBase.java
+++ b/tests/src/com/android/inputmethod/keyboard/KeyboardLayoutSetTestsBase.java
@@ -51,7 +51,7 @@
     protected void setUp() throws Exception {
         super.setUp();
         final KeyboardTheme keyboardTheme = KeyboardTheme.searchKeyboardThemeById(
-                getKeyboardThemeForTests());
+                getKeyboardThemeForTests(), KeyboardTheme.KEYBOARD_THEMES);
         setContext(new ContextThemeWrapper(getContext(), keyboardTheme.mStyleId));
         KeyboardLayoutSet.onKeyboardThemeChanged();
 
diff --git a/tests/src/com/android/inputmethod/keyboard/KeyboardThemeTests.java b/tests/src/com/android/inputmethod/keyboard/KeyboardThemeTests.java
index c20954f..34cf407 100644
--- a/tests/src/com/android/inputmethod/keyboard/KeyboardThemeTests.java
+++ b/tests/src/com/android/inputmethod/keyboard/KeyboardThemeTests.java
@@ -28,6 +28,8 @@
 import android.test.AndroidTestCase;
 import android.test.suitebuilder.annotation.SmallTest;
 
+import java.util.Arrays;
+
 @SmallTest
 public class KeyboardThemeTests extends AndroidTestCase {
     private SharedPreferences mPrefs;
@@ -77,7 +79,9 @@
     }
 
     private void assertKeyboardTheme(final int sdkVersion, final int expectedThemeId) {
-        assertEquals(expectedThemeId, KeyboardTheme.getKeyboardTheme(mPrefs, sdkVersion).mThemeId);
+        final KeyboardTheme actualTheme = KeyboardTheme.getKeyboardTheme(
+                mPrefs, sdkVersion, KeyboardTheme.KEYBOARD_THEMES);
+        assertEquals(expectedThemeId, actualTheme.mThemeId);
     }
 
     /*
@@ -139,8 +143,8 @@
         final String oldPrefKey = KeyboardTheme.KLP_KEYBOARD_THEME_KEY;
         setKeyboardThemePreference(oldPrefKey, previousThemeId);
 
-        final KeyboardTheme defaultTheme =
-                KeyboardTheme.getDefaultKeyboardTheme(mPrefs, sdkVersion);
+        final KeyboardTheme defaultTheme = KeyboardTheme.getDefaultKeyboardTheme(
+                mPrefs, sdkVersion, KeyboardTheme.KEYBOARD_THEMES);
 
         assertNotNull(defaultTheme);
         assertEquals(expectedThemeId, defaultTheme.mThemeId);
@@ -194,7 +198,8 @@
         // Clean up new keyboard theme preference to simulate "upgrade to LXX keyboard".
         setKeyboardThemePreference(KeyboardTheme.LXX_KEYBOARD_THEME_KEY, THEME_ID_NULL);
 
-        final KeyboardTheme theme = KeyboardTheme.getKeyboardTheme(mPrefs, sdkVersion);
+        final KeyboardTheme theme = KeyboardTheme.getKeyboardTheme(
+                mPrefs, sdkVersion, KeyboardTheme.KEYBOARD_THEMES);
 
         assertNotNull(theme);
         assertEquals(expectedThemeId, theme.mThemeId);
@@ -341,4 +346,60 @@
         assertUpgradePlatformFromTo(
                 oldSdkVersion, newSdkVersion, THEME_ID_ILLEGAL, THEME_ID_LXX_LIGHT);
     }
+
+    /*
+     * Test for missing selected theme.
+     */
+    private static KeyboardTheme[] LIMITED_THEMES = {
+        KeyboardTheme.searchKeyboardThemeById(THEME_ID_ICS, KeyboardTheme.KEYBOARD_THEMES),
+        KeyboardTheme.searchKeyboardThemeById(THEME_ID_KLP, KeyboardTheme.KEYBOARD_THEMES)
+    };
+    static {
+        Arrays.sort(LIMITED_THEMES);
+    }
+
+    public void testMissingSelectedThemeIcs() {
+        // Clean up preferences.
+        setKeyboardThemePreference(KeyboardTheme.KLP_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+        setKeyboardThemePreference(KeyboardTheme.LXX_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+
+        final int sdkVersion = VERSION_CODES.ICE_CREAM_SANDWICH;
+        final String oldPrefKey = KeyboardTheme.getPreferenceKey(sdkVersion);
+        setKeyboardThemePreference(oldPrefKey, THEME_ID_LXX_LIGHT);
+
+        final KeyboardTheme actualTheme = KeyboardTheme.getKeyboardTheme(
+                mPrefs, sdkVersion, LIMITED_THEMES);
+        // LXX_LIGHT is missing, fall-back to KLP.
+        assertEquals(THEME_ID_KLP, actualTheme.mThemeId);
+    }
+
+    public void testMissingSelectedThemeKlp() {
+        // Clean up preferences.
+        setKeyboardThemePreference(KeyboardTheme.KLP_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+        setKeyboardThemePreference(KeyboardTheme.LXX_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+
+        final int sdkVersion = VERSION_CODES.KITKAT;
+        final String oldPrefKey = KeyboardTheme.getPreferenceKey(sdkVersion);
+        setKeyboardThemePreference(oldPrefKey, THEME_ID_LXX_LIGHT);
+
+        final KeyboardTheme actualTheme = KeyboardTheme.getKeyboardTheme(
+                mPrefs, sdkVersion, LIMITED_THEMES);
+        // LXX_LIGHT is missing, fall-back to KLP.
+        assertEquals(THEME_ID_KLP, actualTheme.mThemeId);
+    }
+
+    public void testMissingSelectedThemeLxx() {
+        // Clean up preferences.
+        setKeyboardThemePreference(KeyboardTheme.KLP_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+        setKeyboardThemePreference(KeyboardTheme.LXX_KEYBOARD_THEME_KEY, THEME_ID_NULL);
+
+        final int sdkVersion = VERSION_CODES_LXX;
+        final String oldPrefKey = KeyboardTheme.getPreferenceKey(sdkVersion);
+        setKeyboardThemePreference(oldPrefKey, THEME_ID_LXX_DARK);
+
+        final KeyboardTheme actualTheme = KeyboardTheme.getKeyboardTheme(
+                mPrefs, sdkVersion, LIMITED_THEMES);
+        // LXX_DARK is missing, fall-back to KLP.
+        assertEquals(THEME_ID_KLP, actualTheme.mThemeId);
+    }
 }