diff --git a/src-ui/p.html b/src-ui/p.html
index cca58fb68..e6298cf8a 100644
--- a/src-ui/p.html
+++ b/src-ui/p.html
@@ -330,6 +330,12 @@ <h2 id="title2">読み込み中です...</h2>
         <span>__mouseonly__</span>
       </label>
     </div>
+    <div class="config" data-config="patchwork_leftaux">
+      <label>
+        <input type="checkbox">
+        <span>__patchwork_leftaux__</span>
+      </label>
+    </div>
     <div class="config" data-config="keypopup">
       <label>
         <input type="checkbox">
diff --git a/src-ui/res/p.en.json b/src-ui/res/p.en.json
index e561f27e0..1d95bbc88 100644
--- a/src-ui/res/p.en.json
+++ b/src-ui/res/p.en.json
@@ -52,6 +52,7 @@
     "singlenum.menu": "Single number in a region",
     "discolor": "Disable color",
     "mouseonly": "Enable mouse-only input",
+    "patchwork_leftaux": "Enable to input aux. lines with single click",
     "autocheck": "Answer check",
     "autocheck.off": "Manual",
     "autocheck.guarded": "Automatic (guarded)",
diff --git a/src/puzzle/Config.js b/src/puzzle/Config.js
index 42fc6f156..7b39b4e8a 100644
--- a/src/puzzle/Config.js
+++ b/src/puzzle/Config.js
@@ -49,6 +49,10 @@
 			this.add("dispqnumbg", false); /* yinyang: 問題のまるに背景色をつける */
 			this.add("undefcell", true); /* shugaku: 未確定マスはグレー表示にする */
 			this.add("mouseonly", false); /* lollipops: Alternative mouse input */
+			this.add(
+				"patchwork_leftaux",
+				true
+			); /* patchwork: Alternative mouse input */
 
 			this.add("squarecell", true); /* セルは正方形にする */
 
diff --git a/src/variety/patchwork.js b/src/variety/patchwork.js
index 212e4c3f9..81626238a 100644
--- a/src/variety/patchwork.js
+++ b/src/variety/patchwork.js
@@ -26,7 +26,9 @@
 						this.inputShade();
 					}
 				} else if (this.notInputted()) {
-					if (this.isBorderMode()) {
+					if (!this.puzzle.getConfig("patchwork_leftaux")) {
+						this.inputShade();
+					} else if (this.isBorderMode()) {
 						var border = this.getborder();
 						if (!border.isnull) {
 							border.setQsub(border.qsub === 1 ? 0 : 1);