diff --git a/ext/bg/js/search.js b/ext/bg/js/search.js
index ad579918..6f512604 100644
--- a/ext/bg/js/search.js
+++ b/ext/bg/js/search.js
@@ -248,7 +248,7 @@ class DisplaySearch extends Display {
             } else if (IS_FIREFOX === false) {
                 curText = (await apiClipboardGet()).trim();
             }
-            if (curText && (curText !== this.clipboardPrevText)) {
+            if (curText && (curText !== this.clipboardPrevText) && jpIsJapaneseText(curText)) {
                 if (this.isWanakanaEnabled()) {
                     this.query.value = window.wanakana.toKana(curText);
                 } else {
diff --git a/ext/mixed/js/japanese.js b/ext/mixed/js/japanese.js
index 9f401da7..d24f56a6 100644
--- a/ext/mixed/js/japanese.js
+++ b/ext/mixed/js/japanese.js
@@ -26,6 +26,15 @@ function jpIsKana(c) {
     return wanakana.isKana(c);
 }
 
+function jpIsJapaneseText(text) {
+    for (const c of text) {
+        if (jpIsKanji(c) || jpIsKana(c)) {
+            return true;
+        }
+    }
+    return false;
+}
+
 function jpKatakanaToHiragana(text) {
     let result = '';
     for (const c of text) {