diff --git a/api-routes-starter/pages/index.js b/api-routes-starter/pages/index.js
index a71aeb6..31698c5 100644
--- a/api-routes-starter/pages/index.js
+++ b/api-routes-starter/pages/index.js
@@ -22,7 +22,7 @@ export default function Home({ allPostsData }) {
         <h2 className={utilStyles.headingLg}>Blog</h2>
         <ul className={utilStyles.list}>
           {allPostsData.map(({ id, date, title }) => (
-            <li className={utilStyles.listItem}>
+            <li className={utilStyles.listItem} key={id}>
               <Link href="/posts/[id]" as={`/posts/${id}`}>
                 <a>{title}</a>
               </Link>
diff --git a/basics-final/pages/index.js b/basics-final/pages/index.js
index caad2ae..c4abb5a 100644
--- a/basics-final/pages/index.js
+++ b/basics-final/pages/index.js
@@ -28,7 +28,7 @@ export default function Home({ allPostsData }) {
         <h2 className={utilStyles.headingLg}>Blog</h2>
         <ul className={utilStyles.list}>
           {allPostsData.map(({ id, date, title }) => (
-            <li className={utilStyles.listItem}>
+            <li className={utilStyles.listItem} key={id}>
               <Link href="/posts/[id]" as={`/posts/${id}`}>
                 <a>{title}</a>
               </Link>
diff --git a/dynamic-routes-starter/pages/index.js b/dynamic-routes-starter/pages/index.js
index e437161..1065af2 100644
--- a/dynamic-routes-starter/pages/index.js
+++ b/dynamic-routes-starter/pages/index.js
@@ -16,7 +16,7 @@ export default function Home({ allPostsData }) {
         <h2 className={utilStyles.headingLg}>Blog</h2>
         <ul className={utilStyles.list}>
           {allPostsData.map(({ id, date, title }) => (
-            <li className={utilStyles.listItem}>
+            <li className={utilStyles.listItem} key={id}>
               {title}
               <br />
               {id}
diff --git a/typescript-starter/pages/index.js b/typescript-starter/pages/index.js
index a71aeb6..31698c5 100644
--- a/typescript-starter/pages/index.js
+++ b/typescript-starter/pages/index.js
@@ -22,7 +22,7 @@ export default function Home({ allPostsData }) {
         <h2 className={utilStyles.headingLg}>Blog</h2>
         <ul className={utilStyles.list}>
           {allPostsData.map(({ id, date, title }) => (
-            <li className={utilStyles.listItem}>
+            <li className={utilStyles.listItem} key={id}>
               <Link href="/posts/[id]" as={`/posts/${id}`}>
                 <a>{title}</a>
               </Link>