diff --git a/examples/simple/src/comments/CommentList.js b/examples/simple/src/comments/CommentList.js
index 9c97ff775df..cd5383c736f 100644
--- a/examples/simple/src/comments/CommentList.js
+++ b/examples/simple/src/comments/CommentList.js
@@ -125,7 +125,7 @@ const CommentGrid = ({ ids, data, basePath }) => {
     const classes = useListStyles();
 
     return (
-        <Grid spacing={2} container style={{ padding: '0 1em' }}>
+        <Grid spacing={2} container>
             {ids.map(id => (
                 <Grid item key={id} sm={12} md={6} lg={4}>
                     <Card className={classes.card}>
diff --git a/examples/simple/src/comments/PostPreview.js b/examples/simple/src/comments/PostPreview.js
index f573f9794d9..2063f2a9a40 100644
--- a/examples/simple/src/comments/PostPreview.js
+++ b/examples/simple/src/comments/PostPreview.js
@@ -11,6 +11,7 @@ const PostPreview = props => {
         [props.resource, props.id],
     );
     const version = useSelector(state => state.admin.ui.viewVersion);
+    const isLoading = useSelector(state => state.admin.loading > 0);
 
     return (
         <SimpleShowLayout version={version} record={record} {...props}>
diff --git a/examples/simple/src/posts/PostCreate.js b/examples/simple/src/posts/PostCreate.js
index f2cb6b4fa13..b0acfaebfb1 100644
--- a/examples/simple/src/posts/PostCreate.js
+++ b/examples/simple/src/posts/PostCreate.js
@@ -29,11 +29,10 @@ const SaveWithNoteButton = props => {
     const { basePath, handleSubmit, redirect } = props;
 
     const handleClick = useCallback(
-        () => {
-            return handleSubmit(values => {
+        () =>
+            handleSubmit(values => {
                 dispatch(saveWithNote(values, basePath, redirect));
-            });
-        },
+            }),
         [basePath, redirect],
     );
 
diff --git a/examples/simple/src/posts/PostList.js b/examples/simple/src/posts/PostList.js
index db5352c066f..574149aa852 100644
--- a/examples/simple/src/posts/PostList.js
+++ b/examples/simple/src/posts/PostList.js
@@ -116,7 +116,7 @@ const PostList = props => {
                     />
                 }
                 medium={
-                    <Datagrid rowClick={rowClick} expand={<PostPanel />}>
+                    <Datagrid rowClick={rowClick} expand={PostPanel}>
                         <TextField source="id" />
                         <TextField
                             source="title"