diff --git a/res/xml-sw768dp/openwnn_pref_ja.xml b/res/xml-sw768dp/openwnn_pref_ja.xml
index 729c7f2..3792496 100644
--- a/res/xml-sw768dp/openwnn_pref_ja.xml
+++ b/res/xml-sw768dp/openwnn_pref_ja.xml
@@ -61,7 +61,7 @@
   </PreferenceCategory>
  
   <PreferenceCategory android:title="@string/preference_dictionary_menu">
-    <PreferenceScreen android:key="user_dictionary_edit_words"
+    <PreferenceScreen android:key="user_dictionary_edit_words_ja"
                       android:title="@string/preference_dictionary_menu_ja"
                       android:summary="@string/preference_user_dictionary_edit_words_summary_ja"
                       android:persistent="false">
@@ -70,7 +70,7 @@
             android:targetClass="jp.co.omronsoft.openwnn.JAJP.UserDictionaryToolsListJAJP" />
     </PreferenceScreen>
  
-    <PreferenceScreen android:key="user_dictionary_edit_words"
+    <PreferenceScreen android:key="user_dictionary_edit_words_en"
                       android:title="@string/preference_dictionary_menu_en"
                       android:summary="@string/preference_user_dictionary_edit_words_summary_en"
                       android:persistent="false">
diff --git a/res/xml/openwnn_pref_ja.xml b/res/xml/openwnn_pref_ja.xml
index bc90ddd..9168fc9 100644
--- a/res/xml/openwnn_pref_ja.xml
+++ b/res/xml/openwnn_pref_ja.xml
@@ -70,7 +70,7 @@
   </PreferenceCategory>
     
   <PreferenceCategory android:title="@string/preference_dictionary_menu">
-    <PreferenceScreen android:key="user_dictionary_edit_words"
+    <PreferenceScreen android:key="user_dictionary_edit_words_ja"
 		      android:title="@string/preference_dictionary_menu_ja"
 		      android:summary="@string/preference_user_dictionary_edit_words_summary_ja"
 		      android:persistent="false">
@@ -79,7 +79,7 @@
 	    android:targetClass="jp.co.omronsoft.openwnn.JAJP.UserDictionaryToolsListJAJP" />
     </PreferenceScreen>
     
-    <PreferenceScreen android:key="user_dictionary_edit_words"
+    <PreferenceScreen android:key="user_dictionary_edit_words_en"
 		      android:title="@string/preference_dictionary_menu_en"
 		      android:summary="@string/preference_user_dictionary_edit_words_summary_en"
 		      android:persistent="false">
diff --git a/src/jp/co/omronsoft/openwnn/OpenWnnControlPanelJAJP.java b/src/jp/co/omronsoft/openwnn/OpenWnnControlPanelJAJP.java
index 9fe9263..46a0900 100644
--- a/src/jp/co/omronsoft/openwnn/OpenWnnControlPanelJAJP.java
+++ b/src/jp/co/omronsoft/openwnn/OpenWnnControlPanelJAJP.java
@@ -18,6 +18,7 @@
 
 import android.os.Bundle;
 import android.preference.PreferenceActivity;
+import android.preference.PreferenceScreen;
 
 /**
  * The control panel preference class for Japanese IME.
@@ -26,6 +27,11 @@
  */
 public class OpenWnnControlPanelJAJP extends PreferenceActivity {
 
+    private static final String KEY_DICTIONARY_JA = "user_dictionary_edit_words_ja";
+    private static final String KEY_DICTIONARY_EN = "user_dictionary_edit_words_en";
+    private PreferenceScreen mJpUserDictPref;
+    private PreferenceScreen mEnUserDictPref;
+
     /** @see android.preference.PreferenceActivity#onCreate */
     @Override public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -34,5 +40,34 @@
         }
 
         addPreferencesFromResource(R.xml.openwnn_pref_ja);
+
+        mJpUserDictPref = (PreferenceScreen) findPreference(KEY_DICTIONARY_JA);
+        mEnUserDictPref = (PreferenceScreen) findPreference(KEY_DICTIONARY_EN);
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        updateUserDictEnableState();
+    }
+
+    private void updateUserDictEnableState() {
+        if (null != mJpUserDictPref) {
+            mJpUserDictPref.setEnabled(isUserDictEnable());
+        }
+        if (null != mEnUserDictPref) {
+            mEnUserDictPref.setEnabled(isUserDictEnable());
+        }
+    }
+    /**
+     * Check whether the user dictionary is available. When current IME isn't
+     * Japanese, OpenWnn.getCurrentIme() returns null. And under this condition,
+     * user dictionary isn't available because mConverterJAJP/mConverterEN will
+     * be null.
+     *
+     * @return true if user dictionary is available.
+     */
+    private boolean isUserDictEnable() {
+        return null != OpenWnn.getCurrentIme();
     }
 }