diff --git a/Source/Modules/WindowControllers/CtlPrefWindow.swift b/Source/Modules/WindowControllers/CtlPrefWindow.swift
index 7d7cf9dd..0722fa7c 100644
--- a/Source/Modules/WindowControllers/CtlPrefWindow.swift
+++ b/Source/Modules/WindowControllers/CtlPrefWindow.swift
@@ -29,7 +29,6 @@ extension NSToolbarItem.Identifier {
 // It should be set as "Preferences" which correspondes to the "Preference" pref pane
 // of this build target.
 class CtlPrefWindow: NSWindowController, NSWindowDelegate {
-  @IBOutlet var fontSizePopUpButton: NSPopUpButton!
   @IBOutlet var uiLanguageButton: NSPopUpButton!
   @IBOutlet var basicKeyboardLayoutButton: NSPopUpButton!
   @IBOutlet var selectionKeyComboBox: NSComboBox!
@@ -267,6 +266,10 @@ class CtlPrefWindow: NSWindowController, NSWindowDelegate {
     }
   }
 
+  @IBAction func toggledExternalFactoryPlistDataOnOff(_: NSButton) {
+    LMMgr.reloadFactoryDictionaryPlists()
+  }
+
   @IBAction func resetSpecifiedUserDataFolder(_: Any) {
     LMMgr.resetSpecifiedUserDataFolder()
   }
diff --git a/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib b/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib
index 0f083af5..032ce3e1 100644
--- a/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib
+++ b/Source/WindowNIBs/Base.lproj/frmPrefWindow.xib
@@ -19,7 +19,6 @@
                 <outlet property="cmbCandidateFontSize" destination="90" id="K27-YZ-Iki"/>
                 <outlet property="cmbPEDataTypeMenu" destination="Hdr-Qr-1qw" id="6Dv-pj-1EE"/>
                 <outlet property="cmbPEInputModeMenu" destination="y5f-AO-wKG" id="hW9-zZ-t8S"/>
-                <outlet property="fontSizePopUpButton" destination="90" id="108"/>
                 <outlet property="lblCurrentlySpecifiedUserDataFolder" destination="REC-r4-T7m" id="eEq-XN-mMq"/>
                 <outlet property="selectionKeyComboBox" destination="uHU-aL-du7" id="cEx-Ui-Phc"/>
                 <outlet property="tfdPETextEditor" destination="kSG-dz-P2N" id="aiA-EA-Isg"/>
@@ -876,14 +875,14 @@
         </view>
         <userDefaultsController representsSharedInstance="YES" id="32"/>
         <view id="Rnp-LM-RIF" userLabel="vwrDictionary">
-            <rect key="frame" x="0.0" y="0.0" width="445" height="284"/>
+            <rect key="frame" x="0.0" y="0.0" width="445" height="316"/>
             <autoresizingMask key="autoresizingMask"/>
             <subviews>
                 <stackView distribution="fill" orientation="vertical" alignment="leading" spacing="6" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" translatesAutoresizingMaskIntoConstraints="NO" id="6xK-1z-A14">
-                    <rect key="frame" x="20" y="34" width="407" height="230"/>
+                    <rect key="frame" x="20" y="45" width="407" height="251"/>
                     <subviews>
                         <textField autoresizesSubviews="NO" horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="FUV-qx-xkC">
-                            <rect key="frame" x="-2" y="215" width="388" height="15"/>
+                            <rect key="frame" x="-2" y="236" width="388" height="15"/>
                             <textFieldCell key="cell" lineBreakMode="clipping" title="Choose your desired user data folder path. Will be omitted if invalid." id="wN3-k3-b2a">
                                 <font key="font" metaFont="cellTitle"/>
                                 <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
@@ -891,7 +890,7 @@
                             </textFieldCell>
                         </textField>
                         <stackView distribution="fill" orientation="horizontal" alignment="bottom" spacing="0.0" horizontalStackHuggingPriority="249.99998474121094" verticalStackHuggingPriority="249.99998474121094" translatesAutoresizingMaskIntoConstraints="NO" id="uUS-Ni-jFP">
-                            <rect key="frame" x="0.0" y="189" width="407" height="20"/>
+                            <rect key="frame" x="0.0" y="210" width="407" height="20"/>
                             <subviews>
                                 <textField verticalHuggingPriority="750" horizontalCompressionResistancePriority="250" textCompletion="NO" translatesAutoresizingMaskIntoConstraints="NO" id="s7t-Kk-EPu">
                                     <rect key="frame" x="0.0" y="0.0" width="347" height="19"/>
@@ -950,7 +949,7 @@
                             </customSpacing>
                         </stackView>
                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="p7V-IN-OTr">
-                            <rect key="frame" x="-1" y="167.5" width="336" height="16"/>
+                            <rect key="frame" x="-1" y="188.5" width="336" height="16"/>
                             <buttonCell key="cell" type="check" title="Automatically reload user data files if changes detected" bezelStyle="regularSquare" imagePosition="left" controlSize="small" state="on" inset="2" id="f8i-69-zxm">
                                 <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
                                 <font key="font" metaFont="cellTitle"/>
@@ -959,6 +958,17 @@
                                 <binding destination="32" name="value" keyPath="values.ShouldAutoReloadUserDataFiles" id="XTI-ol-DVN"/>
                             </connections>
                         </button>
+                        <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="MJ6-U4-qyl">
+                            <rect key="frame" x="-1" y="167.5" width="297" height="16"/>
+                            <buttonCell key="cell" type="check" title="Read external factory dictionary plists if possible" bezelStyle="regularSquare" imagePosition="left" controlSize="small" state="on" inset="2" id="fEA-Bp-Ayn" userLabel="chkUseExternalFactoryDict">
+                                <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                                <font key="font" metaFont="cellTitle"/>
+                            </buttonCell>
+                            <connections>
+                                <action selector="toggledExternalFactoryPlistDataOnOff:" target="-2" id="TYX-1b-x0P"/>
+                                <binding destination="32" name="value" keyPath="values.UseExternalFactoryDict" id="1Gp-Ax-mRK"/>
+                            </connections>
+                        </button>
                         <button verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="ZQK-w3-FRb">
                             <rect key="frame" x="-1" y="146.5" width="274" height="16"/>
                             <buttonCell key="cell" type="check" title="Only load factory language models if needed" bezelStyle="regularSquare" imagePosition="left" controlSize="small" state="on" inset="2" id="chkOnlyLoadFactoryLangModelsIfNeeded" userLabel="chkOnlyLoadFactoryLangModelsIfNeeded">
@@ -1055,6 +1065,7 @@
                         <integer value="1000"/>
                         <integer value="1000"/>
                         <integer value="1000"/>
+                        <integer value="1000"/>
                     </visibilityPriorities>
                     <customSpacing>
                         <real value="3.4028234663852886e+38"/>
@@ -1068,6 +1079,7 @@
                         <real value="3.4028234663852886e+38"/>
                         <real value="3.4028234663852886e+38"/>
                         <real value="3.4028234663852886e+38"/>
+                        <real value="3.4028234663852886e+38"/>
                     </customSpacing>
                 </stackView>
             </subviews>
@@ -1075,7 +1087,7 @@
                 <constraint firstItem="6xK-1z-A14" firstAttribute="top" secondItem="Rnp-LM-RIF" secondAttribute="top" constant="20" symbolic="YES" id="W7P-xQ-mDE"/>
                 <constraint firstItem="6xK-1z-A14" firstAttribute="leading" secondItem="Rnp-LM-RIF" secondAttribute="leading" constant="20" symbolic="YES" id="zFW-2a-uC3"/>
             </constraints>
-            <point key="canvasLocation" x="101.5" y="178"/>
+            <point key="canvasLocation" x="93.5" y="217"/>
         </view>
         <view id="ZEr-3U-K9a" userLabel="vwrCassette">
             <rect key="frame" x="0.0" y="0.0" width="445" height="488"/>
@@ -1755,7 +1767,7 @@
                             <rect key="frame" x="0.0" y="80" width="538" height="360"/>
                             <clipView key="contentView" drawsBackground="NO" id="x8s-wo-bxi">
                                 <rect key="frame" x="0.0" y="0.0" width="538" height="360"/>
-                                <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                                <autoresizingMask key="autoresizingMask"/>
                                 <subviews>
                                     <textView wantsLayer="YES" importsGraphics="NO" richText="NO" verticallyResizable="YES" allowsUndo="YES" smartInsertDelete="YES" id="kSG-dz-P2N">
                                         <rect key="frame" x="0.0" y="0.0" width="538" height="360"/>
diff --git a/Source/WindowNIBs/en.lproj/frmPrefWindow.strings b/Source/WindowNIBs/en.lproj/frmPrefWindow.strings
index 06b37894..70fefd66 100644
--- a/Source/WindowNIBs/en.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/en.lproj/frmPrefWindow.strings
@@ -61,6 +61,7 @@
 "eia-1F-Do0.title" = "Auto-convert traditional Chinese glyphs to JIS Shinjitai characters";
 "f2j-xD-4xK.title" = "Use ESC key to clear the entire input buffer";
 "f8i-69-zxm.title" = "Automatically reload user data files if changes detected";
+"fEA-Bp-Ayn.title" = "Read external factory dictionary plists if possible";
 "FnD-oH-El5.title" = "Selection Keys:";
 "fQ0-Yu-pJF.title" = "Enforce conversion in both input modes";
 "FSG-lN-CJO.title" = "English";
diff --git a/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings b/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings
index c22b46df..3b4f31f5 100644
--- a/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/ja.lproj/frmPrefWindow.strings
@@ -61,6 +61,7 @@
 "eia-1F-Do0.title" = "入力した繁体字を日文 JIS 新字体と自動変換";
 "f2j-xD-4xK.title" = "ESC キーで入力緩衝列を消す";
 "f8i-69-zxm.title" = "変更されたユーザー辞書データを自動的に再読込";
+"fEA-Bp-Ayn.title" = "なるべく（内蔵辞書より）外部の公式辞書ファイルを利用";
 "FnD-oH-El5.title" = "言選り用キー:";
 "fQ0-Yu-pJF.title" = "カセットモードによる漢字出力の簡体繁体転換を常に行う";
 "FSG-lN-CJO.title" = "英語";
diff --git a/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings b/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings
index 22615bda..adecf801 100644
--- a/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/zh-Hans.lproj/frmPrefWindow.strings
@@ -61,6 +61,7 @@
 "eia-1F-Do0.title" = "自动将繁体中文字转换为日本简化字（JIS 新字体）";
 "f2j-xD-4xK.title" = "敲 ESC 键以清空整个输入缓冲区";
 "f8i-69-zxm.title" = "自动重新加载变更过的使用者资料内容";
+"fEA-Bp-Ayn.title" = "尽量使用外置原厂辞典 plist 档案";
 "FnD-oH-El5.title" = "选字键:";
 "fQ0-Yu-pJF.title" = "依当前简繁模式强制转换";
 "FSG-lN-CJO.title" = "英文";
diff --git a/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings b/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings
index 4e42c1c3..deda1a7b 100644
--- a/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings
+++ b/Source/WindowNIBs/zh-Hant.lproj/frmPrefWindow.strings
@@ -61,6 +61,7 @@
 "eia-1F-Do0.title" = "自動將繁體中文字轉換為日本簡化字（JIS 新字體）";
 "f2j-xD-4xK.title" = "敲 ESC 鍵以清空整個輸入緩衝區";
 "f8i-69-zxm.title" = "自動重新載入變更過的使用者資料內容";
+"fEA-Bp-Ayn.title" = "盡量使用外置原廠辭典 plist 檔案";
 "FnD-oH-El5.title" = "選字鍵:";
 "fQ0-Yu-pJF.title" = "依當前簡繁模式強制轉換";
 "FSG-lN-CJO.title" = "英文";