diff --git a/conflu.js b/conflu.js
index 5008da4..95a0435 100644
--- a/conflu.js
+++ b/conflu.js
@@ -1,4 +1,4 @@
-let previousCursorPosition = 0;
+let previousCursorPosition = -1;
 const keydownHandler = (event) => {
     const activeField = document.activeElement;
     // role="textbox"の場合は、カーソル位置を取得
@@ -7,7 +7,7 @@ const keydownHandler = (event) => {
         const cursorPosition = selection.anchorOffset;
 
         // 入力カーソル位置が 1 以外から 1 に変わった場合
-        if ((previousCursorPosition !== 1 && previousCursorPosition !== 0) && cursorPosition === 1 && (event.key === "Process" || event.key == "Shift")) {
+        if (previousCursorPosition !== cursorPosition && cursorPosition === 1 && (event.key === "Process" || event.key == "Shift")) {
             activeField.focus();
             document.execCommand('insertText', false, ' ');
         }