diff --git a/res/layout/extra_keys_preference.xml b/res/layout/extra_keys_preference.xml
new file mode 100644
index 0000000..40bbfbe
--- /dev/null
+++ b/res/layout/extra_keys_preference.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingEnd="?android:attr/scrollbarSize" android:background="?android:attr/selectableItemBackground">
+  <!-- Preference layout that do not define the text view with id 'title'. -->
+  <LinearLayout android:id="@android:id/widget_frame" android:layout_width="wrap_content" android:layout_height="match_parent" android:gravity="center_vertical" android:orientation="vertical"/>
+</LinearLayout>
diff --git a/res/xml/settings.xml b/res/xml/settings.xml
index 322bf4d..f57d58a 100644
--- a/res/xml/settings.xml
+++ b/res/xml/settings.xml
@@ -7,42 +7,7 @@
     <ListPreference android:key="show_numpad" android:title="@string/pref_show_numpad_title" android:summary="%s" android:defaultValue="1" android:entries="@array/pref_show_numpad_entries" android:entryValues="@array/pref_show_numpad_values"/>
     <CheckBoxPreference android:key="number_row" android:title="@string/pref_number_row_title" android:summary="@string/pref_number_row_summary" android:defaultValue="false"/>
     <PreferenceScreen android:title="@string/pref_extra_keys_title">
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="0"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="1"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="2"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="3"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="4"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="5"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="6"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="7"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="8"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="9"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="10"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="11"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="12"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="13"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="14"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="15"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="16"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="17"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="18"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="19"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="20"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="21"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="22"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="23"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="24"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="25"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="26"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="27"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="28"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="29"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="30"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="31"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="32"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="33"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="34"/>
-      <juloo.keyboard2.ExtraKeyCheckBoxPreference app:index="35"/>
+      <juloo.keyboard2.ExtraKeysPreference/>
     </PreferenceScreen>
     <ListPreference android:key="numpad_layout" android:title="@string/pref_numpad_layout" android:summary="%s" android:defaultValue="high_first" android:entries="@array/pref_numpad_layout_entries" android:entryValues="@array/pref_numpad_layout_values"/>
   </PreferenceCategory>
diff --git a/srcs/juloo.keyboard2/Config.java b/srcs/juloo.keyboard2/Config.java
index 2c48b3f..1bc406c 100644
--- a/srcs/juloo.keyboard2/Config.java
+++ b/srcs/juloo.keyboard2/Config.java
@@ -154,7 +154,7 @@ final class Config
     theme = getThemeId(res, _prefs.getString("theme", ""));
     autocapitalisation = _prefs.getBoolean("autocapitalisation", true);
     switch_input_immediate = _prefs.getBoolean("switch_input_immediate", false);
-    extra_keys_param = ExtraKeyCheckBoxPreference.get_extra_keys(_prefs);
+    extra_keys_param = ExtraKeysPreference.get_extra_keys(_prefs);
   }
 
   KeyValue action_key()
diff --git a/srcs/juloo.keyboard2/ExtraKeyCheckBoxPreference.java b/srcs/juloo.keyboard2/ExtraKeyCheckBoxPreference.java
deleted file mode 100644
index 8f7471a..0000000
--- a/srcs/juloo.keyboard2/ExtraKeyCheckBoxPreference.java
+++ /dev/null
@@ -1,110 +0,0 @@
-package juloo.keyboard2;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.content.SharedPreferences;
-import android.preference.CheckBoxPreference;
-import android.util.AttributeSet;
-import android.view.View;
-import android.widget.TextView;
-import java.util.HashSet;
-import java.util.Set;
-
-public class ExtraKeyCheckBoxPreference extends CheckBoxPreference
-{
-  public static String[] extra_keys = new String[]
-  {
-    "alt",
-    "meta",
-    "voice_typing",
-    "accent_aigu",
-    "accent_grave",
-    "accent_double_aigu",
-    "accent_dot_above",
-    "accent_circonflexe",
-    "accent_tilde",
-    "accent_cedille",
-    "accent_trema",
-    "accent_ring",
-    "accent_caron",
-    "accent_macron",
-    "accent_ogonek",
-    "accent_breve",
-    "accent_slash",
-    "accent_bar",
-    "accent_dot_below",
-    "accent_hook_above",
-    "accent_horn",
-    "€",
-    "ß",
-    "£",
-    "switch_greekmath",
-    "capslock",
-    "copy",
-    "paste",
-    "cut",
-    "selectAll",
-    "shareText",
-    "pasteAsPlainText",
-    "undo",
-    "redo",
-    "replaceText",
-    "textAssist",
-    "autofill",
-  };
-
-  public static boolean default_checked(String name)
-  {
-    switch (name)
-    {
-      case "voice_typing":
-        return true;
-      default:
-        return false;
-    }
-  }
-
-  boolean _key_font;
-
-  public ExtraKeyCheckBoxPreference(Context context, AttributeSet attrs)
-  {
-    super(context, attrs);
-    final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ExtraKeyCheckBoxPreference);
-    int index = a.getInteger(R.styleable.ExtraKeyCheckBoxPreference_index, 0);
-    a.recycle();
-    String key_name = extra_keys[index];
-    KeyValue kv = KeyValue.getKeyByName(key_name);
-    String title = kv.getString();
-    String descr = KeyValue.getKeyDescription(key_name);
-    if (descr != null)
-      title += " (" + descr + ")";
-    setKey(pref_key_of_key_name(key_name));
-    setDefaultValue(default_checked(key_name));
-    setTitle(title);
-    _key_font = kv.hasFlags(KeyValue.FLAG_KEY_FONT);
-  }
-
-  @Override
-  protected void onBindView(View view)
-  {
-    super.onBindView(view);
-    TextView title = (TextView)view.findViewById(android.R.id.title);
-    title.setTypeface(_key_font ? Theme.getKeyFont(getContext()) : null);
-  }
-
-  static String pref_key_of_key_name(String key_name)
-  {
-    return "extra_key_" + key_name;
-  }
-
-  public static Set<KeyValue> get_extra_keys(SharedPreferences prefs)
-  {
-    HashSet<KeyValue> ks = new HashSet<KeyValue>();
-    for (String key_name : extra_keys)
-    {
-      if (prefs.getBoolean(pref_key_of_key_name(key_name), default_checked(key_name)))
-        ks.add(KeyValue.getKeyByName(key_name));
-    }
-    return ks;
-  }
-}
diff --git a/srcs/juloo.keyboard2/ExtraKeysPreference.java b/srcs/juloo.keyboard2/ExtraKeysPreference.java
new file mode 100644
index 0000000..698e344
--- /dev/null
+++ b/srcs/juloo.keyboard2/ExtraKeysPreference.java
@@ -0,0 +1,136 @@
+package juloo.keyboard2;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.res.Resources;
+import android.preference.CheckBoxPreference;
+import android.preference.PreferenceGroup;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.TextView;
+import java.util.HashSet;
+import java.util.Set;
+
+/** This class implements the "extra keys" preference but also defines the
+    possible extra keys. */
+public class ExtraKeysPreference extends PreferenceGroup
+{
+  public static String[] extra_keys = new String[]
+  {
+    "alt",
+    "meta",
+    "voice_typing",
+    "accent_aigu",
+    "accent_grave",
+    "accent_double_aigu",
+    "accent_dot_above",
+    "accent_circonflexe",
+    "accent_tilde",
+    "accent_cedille",
+    "accent_trema",
+    "accent_ring",
+    "accent_caron",
+    "accent_macron",
+    "accent_ogonek",
+    "accent_breve",
+    "accent_slash",
+    "accent_bar",
+    "accent_dot_below",
+    "accent_hook_above",
+    "accent_horn",
+    "€",
+    "ß",
+    "£",
+    "switch_greekmath",
+    "capslock",
+    "copy",
+    "paste",
+    "cut",
+    "selectAll",
+    "shareText",
+    "pasteAsPlainText",
+    "undo",
+    "redo",
+    "replaceText",
+    "textAssist",
+    "autofill",
+  };
+
+  /** Whether an extra key is enabled by default. */
+  public static boolean default_checked(String name)
+  {
+    switch (name)
+    {
+      case "voice_typing":
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  /** Get the set of enabled extra keys. */
+  public static Set<KeyValue> get_extra_keys(SharedPreferences prefs)
+  {
+    HashSet<KeyValue> ks = new HashSet<KeyValue>();
+    for (String key_name : extra_keys)
+    {
+      if (prefs.getBoolean(pref_key_of_key_name(key_name),
+            default_checked(key_name)))
+        ks.add(KeyValue.getKeyByName(key_name));
+    }
+    return ks;
+  }
+
+  boolean _attached; /** Whether it has already been attached. */
+
+  public ExtraKeysPreference(Context context, AttributeSet attrs)
+  {
+    super(context, attrs);
+    Resources res = context.getResources();
+    setOrderingAsAdded(true);
+    setLayoutResource(R.layout.extra_keys_preference);
+  }
+
+  protected void onAttachedToActivity()
+  {
+    if (_attached)
+      return;
+    _attached = true;
+    for (String key_name : extra_keys)
+      addPreference(new ExtraKeyCheckBoxPreference(getContext(), key_name,
+            default_checked(key_name)));
+  }
+
+  public static String pref_key_of_key_name(String key_name)
+  {
+    return "extra_key_" + key_name;
+  }
+
+  final class ExtraKeyCheckBoxPreference extends CheckBoxPreference
+  {
+    boolean _key_font;
+
+    public ExtraKeyCheckBoxPreference(Context context, String key_name,
+        boolean default_checked)
+    {
+      super(context);
+      KeyValue kv = KeyValue.getKeyByName(key_name);
+      String title = kv.getString();
+      String descr = KeyValue.getKeyDescription(key_name);
+      if (descr != null)
+        title += " (" + descr + ")";
+      setKey(pref_key_of_key_name(key_name));
+      setDefaultValue(default_checked);
+      setTitle(title);
+      _key_font = kv.hasFlags(KeyValue.FLAG_KEY_FONT);
+    }
+
+    @Override
+    protected void onBindView(View view)
+    {
+      super.onBindView(view);
+      TextView title = (TextView)view.findViewById(android.R.id.title);
+      title.setTypeface(_key_font ? Theme.getKeyFont(getContext()) : null);
+    }
+  }
+}