diff --git a/src/basic.ts b/src/basic.ts
index 5b56d70..42bc5fd 100644
--- a/src/basic.ts
+++ b/src/basic.ts
@@ -154,6 +154,10 @@ export class BasicTool {
     return Zotero.platformMajorVersion >= 102;
   }
 
+  isFX115(): boolean {
+    return Zotero.platformMajorVersion >= 115;
+  }
+
   /**
    * Get DOMParser.
    *
diff --git a/src/helpers/clipboard.ts b/src/helpers/clipboard.ts
index eeefa10..a8ed88e 100644
--- a/src/helpers/clipboard.ts
+++ b/src/helpers/clipboard.ts
@@ -42,12 +42,14 @@ export class ClipboardHelper extends BasicTool {
 
   public addText(
     source: string,
-    type: "text/html" | "text/unicode" = "text/unicode"
+    type: "text/html" | "text/plain" | "text/unicode" = "text/plain"
   ) {
     const str = Components.classes[
       "@mozilla.org/supports-string;1"
     ].createInstance(Components.interfaces.nsISupportsString);
     str.data = source;
+    // Compatible to text/unicode in fx115
+    if (this.isFX115() && type === "text/unicode") type = "text/plain";
     this.transferable.addDataFlavor(type);
     this.transferable.setTransferData(type, str, source.length * 2);
     return this;