diff --git a/app/src/protyle/util/compatibility.ts b/app/src/protyle/util/compatibility.ts
index 8c8967311..df6a36693 100644
--- a/app/src/protyle/util/compatibility.ts
+++ b/app/src/protyle/util/compatibility.ts
@@ -98,6 +98,10 @@ export const readText = () => {
     } else if (isInHarmony()) {
         return window.JSHarmony.readClipboard();
     }
+    if (typeof navigator.clipboard === "undefined") {
+        alert(window.siyuan.languages.clipboardPermissionDenied);
+        return "";
+    }
     return navigator.clipboard.readText().catch(() => {
         alert(window.siyuan.languages.clipboardPermissionDenied);
     }) || "";
@@ -142,6 +146,10 @@ export const readClipboard = async () => {
         text.siyuanHTML = textObj.textSiyuan;
         return text;
     }
+    if (typeof navigator.clipboard === "undefined") {
+        alert(window.siyuan.languages.clipboardPermissionDenied);
+        return text;
+    }
     try {
         const clipboardContents = await navigator.clipboard.read().catch(() => {
             alert(window.siyuan.languages.clipboardPermissionDenied);