diff --git a/cypress/integration/edit.js b/cypress/integration/edit.js
index d23df5aefa9..496e27277e4 100644
--- a/cypress/integration/edit.js
+++ b/cypress/integration/edit.js
@@ -69,6 +69,17 @@ describe('Edit Page', () => {
             );
         });
 
+        it('should validate inputs inside ArrayInput', () => {
+            EditPostPage.gotoTab(3);
+
+            cy.get(EditPostPage.elements.addBacklinkButton).click();
+
+            EditPostPage.clickInput('backlinks[0].url');
+            cy.get(EditPostPage.elements.input('backlinks[0].url')).blur();
+
+            cy.contains('Required');
+        });
+
         it('should change reference list correctly when changing filter', () => {
             const EditPostTagsPage = editPageFactory('/#/posts/13');
             EditPostTagsPage.navigate();
diff --git a/cypress/support/EditPage.js b/cypress/support/EditPage.js
index 4a9314028fc..b9c80aa473e 100644
--- a/cypress/support/EditPage.js
+++ b/cypress/support/EditPage.js
@@ -2,6 +2,7 @@ export default url => ({
     elements: {
         body: 'body',
         deleteButton: '.ra-delete-button',
+        addBacklinkButton: '.button-add-backlinks',
         input: (name, type = 'input') => {
             if (type === 'rich-text-input') {
                 return `.ra-input-${name} .ql-editor`;
diff --git a/examples/simple/src/posts/PostEdit.js b/examples/simple/src/posts/PostEdit.js
index 371b9155382..de8a6a5e0dc 100644
--- a/examples/simple/src/posts/PostEdit.js
+++ b/examples/simple/src/posts/PostEdit.js
@@ -144,7 +144,7 @@ const PostEdit = ({ permissions, ...props }) => (
                 <ArrayInput source="backlinks">
                     <SimpleFormIterator>
                         <DateInput source="date" />
-                        <TextInput source="url" />
+                        <TextInput source="url" validate={required()} />
                     </SimpleFormIterator>
                 </ArrayInput>
                 <DateInput source="published_at" options={{ locale: 'pt' }} />
diff --git a/packages/ra-core/src/form/useFormGroup.ts b/packages/ra-core/src/form/useFormGroup.ts
index 3936912f772..f5a6dbe2005 100644
--- a/packages/ra-core/src/form/useFormGroup.ts
+++ b/packages/ra-core/src/form/useFormGroup.ts
@@ -5,11 +5,12 @@ import { useFormContext } from './useFormContext';
 import { FieldState } from 'final-form';
 
 type FormGroupState = {
+    dirty: boolean;
     errors: object;
-    valid: boolean;
     invalid: boolean;
     pristine: boolean;
-    dirty: boolean;
+    touched: boolean;
+    valid: boolean;
 };
 
 /**
@@ -58,18 +59,23 @@ export const useFormGroup = (name: string): FormGroupState => {
     const form = useForm();
     const formContext = useFormContext();
     const [state, setState] = useState<FormGroupState>({
+        dirty: false,
         errors: undefined,
-        valid: true,
         invalid: false,
         pristine: true,
-        dirty: false,
+        touched: false,
+        valid: true,
     });
 
     useEffect(() => {
         const unsubscribe = form.subscribe(
             () => {
                 const fields = formContext.getGroupFields(name);
-                const fieldStates = fields.map(form.getFieldState);
+                const fieldStates = fields
+                    .map(field => {
+                        return form.getFieldState(field);
+                    })
+                    .filter(fieldState => fieldState != undefined); // eslint-disable-line
                 const newState = getFormGroupState(fieldStates);
 
                 setState(oldState => {
@@ -86,6 +92,7 @@ export const useFormGroup = (name: string): FormGroupState => {
                 dirty: true,
                 pristine: true,
                 valid: true,
+                touched: true,
             }
         );
         return unsubscribe;
@@ -102,8 +109,8 @@ export const useFormGroup = (name: string): FormGroupState => {
  */
 export const getFormGroupState = (
     fieldStates: FieldState<any>[]
-): FormGroupState =>
-    fieldStates.reduce(
+): FormGroupState => {
+    return fieldStates.reduce(
         (acc, fieldState) => {
             let errors = acc.errors || {};
 
@@ -112,20 +119,23 @@ export const getFormGroupState = (
             }
 
             const newState = {
+                dirty: acc.dirty || fieldState.dirty,
                 errors,
-                valid: acc.valid && fieldState.valid,
                 invalid: acc.invalid || fieldState.invalid,
                 pristine: acc.pristine && fieldState.pristine,
-                dirty: acc.dirty || fieldState.dirty,
+                touched: acc.touched || fieldState.touched,
+                valid: acc.valid && fieldState.valid,
             };
 
             return newState;
         },
         {
+            dirty: false,
             errors: undefined,
-            valid: true,
             invalid: false,
             pristine: true,
-            dirty: false,
+            valid: true,
+            touched: false,
         }
     );
+};
diff --git a/packages/ra-ui-materialui/src/form/FormTab.tsx b/packages/ra-ui-materialui/src/form/FormTab.tsx
index cf369b97945..3cfd3271370 100644
--- a/packages/ra-ui-materialui/src/form/FormTab.tsx
+++ b/packages/ra-ui-materialui/src/form/FormTab.tsx
@@ -93,7 +93,7 @@ export const FormTabHeader = ({
             className={classnames('form-tab', className, {
                 [classes.errorTabButton]:
                     formGroup.invalid &&
-                    formGroup.dirty &&
+                    formGroup.touched &&
                     location.pathname !== value,
             })}
             component={Link}
diff --git a/packages/ra-ui-materialui/src/input/TranslatableInputsTab.tsx b/packages/ra-ui-materialui/src/input/TranslatableInputsTab.tsx
index ab23914f491..9a48783ffb1 100644
--- a/packages/ra-ui-materialui/src/input/TranslatableInputsTab.tsx
+++ b/packages/ra-ui-materialui/src/input/TranslatableInputsTab.tsx
@@ -13,7 +13,8 @@ export const TranslatableInputsTab = (
     props: TranslatableInputsTabProps & TabProps
 ) => {
     const { groupKey = '', locale, classes: classesOverride, ...rest } = props;
-    const { invalid } = useFormGroup(`${groupKey}${locale}`);
+    const { invalid, touched } = useFormGroup(`${groupKey}${locale}`);
+
     const classes = useStyles(props);
     const translate = useTranslate();
 
@@ -23,7 +24,7 @@ export const TranslatableInputsTab = (
             label={translate(`ra.locales.${locale}`, {
                 _: capitalize(locale),
             })}
-            className={invalid ? classes.error : undefined}
+            className={invalid && touched ? classes.error : undefined}
             {...rest}
         />
     );