diff --git a/examples/simple/src/Layout.tsx b/examples/simple/src/Layout.tsx
index e9f6fe04037..60037a64cd3 100644
--- a/examples/simple/src/Layout.tsx
+++ b/examples/simple/src/Layout.tsx
@@ -1,7 +1,7 @@
 import * as React from 'react';
 import { forwardRef, memo } from 'react';
 import { Layout, AppBar, UserMenu, useLocale, useSetLocale } from 'react-admin';
-import { MenuItem, ListItemIcon } from '@material-ui/core';
+import { MenuItem, ListItemIcon, MenuItemProps } from '@material-ui/core';
 import { makeStyles } from '@material-ui/core/styles';
 import Language from '@material-ui/icons/Language';
 
@@ -12,7 +12,7 @@ const useStyles = makeStyles(theme => ({
     icon: { minWidth: theme.spacing(5) },
 }));
 
-const SwitchLanguage = forwardRef((props, ref) => {
+const SwitchLanguage = forwardRef((props: MenuItemProps, ref) => {
     const locale = useLocale();
     const setLocale = useSetLocale();
     const classes = useStyles();
@@ -20,9 +20,9 @@ const SwitchLanguage = forwardRef((props, ref) => {
         <MenuItem
             ref={ref}
             className={classes.menuItem}
-            onClick={() => {
+            onClick={e => {
                 setLocale(locale === 'en' ? 'fr' : 'en');
-                props.onClick();
+                props.onClick(e);
             }}
         >
             <ListItemIcon className={classes.icon}>
diff --git a/examples/simple/src/authProvider.tsx b/examples/simple/src/authProvider.tsx
index 50ca0660941..08249bcbcd3 100644
--- a/examples/simple/src/authProvider.tsx
+++ b/examples/simple/src/authProvider.tsx
@@ -34,11 +34,11 @@ export default {
             );
             return Promise.resolve();
         }
-        localStorage.setItem('not_authenticated', true);
+        localStorage.setItem('not_authenticated', 'true');
         return Promise.reject();
     },
     logout: () => {
-        localStorage.setItem('not_authenticated', true);
+        localStorage.setItem('not_authenticated', 'true');
         localStorage.removeItem('role');
         localStorage.removeItem('login');
         localStorage.removeItem('user');
diff --git a/examples/simple/src/comments/CommentEdit.tsx b/examples/simple/src/comments/CommentEdit.tsx
index 079c0a36477..44ce5bc4d14 100644
--- a/examples/simple/src/comments/CommentEdit.tsx
+++ b/examples/simple/src/comments/CommentEdit.tsx
@@ -156,7 +156,9 @@ const CommentEdit = props => {
                                     optionText={<OptionRenderer />}
                                     inputText={inputText}
                                     options={{
-                                        fullWidth: true,
+                                        InputProps: {
+                                            fullWidth: true,
+                                        },
                                     }}
                                 />
                             </ReferenceInput>
diff --git a/examples/simple/src/customRouteNoLayout.tsx b/examples/simple/src/customRouteNoLayout.tsx
index a06af18b1ea..81477d5b508 100644
--- a/examples/simple/src/customRouteNoLayout.tsx
+++ b/examples/simple/src/customRouteNoLayout.tsx
@@ -1,18 +1,18 @@
 import * as React from 'react';
 import { useEffect } from 'react';
 import { useSelector, useDispatch } from 'react-redux';
-import { crudGetList } from 'react-admin';
+import { crudGetList, ReduxState } from 'react-admin';
 
 const CustomRouteNoLayout = () => {
     const dispatch = useDispatch();
 
     const loaded = useSelector(
-        state =>
+        (state: ReduxState) =>
             state.admin.resources.posts &&
             state.admin.resources.posts.list.total > 0
     );
 
-    const total = useSelector(state =>
+    const total = useSelector((state: ReduxState) =>
         state.admin.resources.posts ? state.admin.resources.posts.list.total : 0
     );
 
@@ -21,7 +21,8 @@ const CustomRouteNoLayout = () => {
             crudGetList(
                 'posts',
                 { page: 0, perPage: 10 },
-                { field: 'id', order: 'ASC' }
+                { field: 'id', order: 'ASC' },
+                {}
             )
         );
     }, [dispatch]);
diff --git a/examples/simple/src/users/UserEdit.tsx b/examples/simple/src/users/UserEdit.tsx
index b62afc9c66b..74da8bae16a 100644
--- a/examples/simple/src/users/UserEdit.tsx
+++ b/examples/simple/src/users/UserEdit.tsx
@@ -5,6 +5,7 @@ import {
     CloneButton,
     DeleteWithConfirmButton,
     Edit,
+    EditActionsProps,
     FormTab,
     required,
     SaveButton,
@@ -42,7 +43,7 @@ const UserEditToolbar = props => {
     );
 };
 
-const EditActions = ({ basePath, data, hasShow }) => (
+const EditActions = ({ basePath, data, hasShow }: EditActionsProps) => (
     <TopToolbar>
         <CloneButton
             className="button-clone"
diff --git a/examples/simple/src/users/UserTitle.tsx b/examples/simple/src/users/UserTitle.tsx
index 574dbbd72c3..4afba957793 100644
--- a/examples/simple/src/users/UserTitle.tsx
+++ b/examples/simple/src/users/UserTitle.tsx
@@ -1,8 +1,8 @@
 /* eslint react/jsx-key: off */
 import * as React from 'react';
-import { useTranslate } from 'react-admin';
+import { Record, useTranslate } from 'react-admin';
 
-const UserTitle = ({ record }) => {
+const UserTitle = ({ record }: { record?: Record }) => {
     const translate = useTranslate();
     return (
         <span>