diff --git a/src/components/common/highlighted-code/highlighted-code.tsx b/src/components/common/highlighted-code/highlighted-code.tsx
index bf537809f..29fdb9c1e 100644
--- a/src/components/common/highlighted-code/highlighted-code.tsx
+++ b/src/components/common/highlighted-code/highlighted-code.tsx
@@ -48,7 +48,7 @@ export const HighlightedCode: React.FC<HighlightedCodeProps> = ({ code, language
           {
             highlightedCode
               .map((line, index) => {
-                return <span data-line-number={index + 1}/>
+                return <span key={index} data-line-number={index + 1}/>
               })
           }
         </span>