diff --git a/src/platforms/GitHub/CopyFileButton.tsx b/src/platforms/GitHub/CopyFileButton.tsx
index 753191b..47d26c0 100644
--- a/src/platforms/GitHub/CopyFileButton.tsx
+++ b/src/platforms/GitHub/CopyFileButton.tsx
@@ -43,7 +43,7 @@ export function CopyFileButton(props: React.PropsWithChildren<Props>) {
   }, [])
 
   return (
-    <a ref={elementRef} className={cx('btn btn-sm BtnGroup-item copy-file-btn', className)}>
+    <a ref={elementRef} className={cx('btn btn-sm BtnGroup-item', className)}>
       {content}
     </a>
   )
diff --git a/src/platforms/GitHub/DOMHelper.ts b/src/platforms/GitHub/DOMHelper.ts
index c5d2b99..146812a 100644
--- a/src/platforms/GitHub/DOMHelper.ts
+++ b/src/platforms/GitHub/DOMHelper.ts
@@ -139,6 +139,13 @@ export function getCodeElement() {
  * click these buttons will copy file content to clipboard
  */
 export function attachCopyFileBtn() {
+  const removeButtons = () => {
+    const buttons = document.querySelectorAll(`.${copyFileButtonClassName}`)
+    buttons.forEach(button => {
+      button.parentElement?.removeChild(button)
+    })
+  }
+
   if (getCurrentPageType() === PAGE_TYPES.RAW_TEXT) {
     // the button group in file content header
     const buttonGroupSelector = '.repository-content .Box-header .BtnGroup'
@@ -148,6 +155,8 @@ export function attachCopyFileBtn() {
       raiseError(new Error(`No button groups found`))
     }
 
+    removeButtons() // prevent duplicated buttons
+
     buttonGroups.forEach(async buttonGroup => {
       if (!buttonGroup.lastElementChild) return
       const button = await renderReact(React.createElement(CopyFileButton))
@@ -158,12 +167,7 @@ export function attachCopyFileBtn() {
   }
 
   // return callback so that disabling after redirecting from file page to non-page works properly
-  return () => {
-    const buttons = document.querySelectorAll(`.${copyFileButtonClassName}`)
-    buttons.forEach(button => {
-      button.parentElement?.removeChild(button)
-    })
-  }
+  return removeButtons
 }
 
 export function attachCopySnippet() {