diff --git a/packages/ra-ui-materialui/src/form/TabbedForm.js b/packages/ra-ui-materialui/src/form/TabbedForm.js
index 69f390c7bb3..f6ff53e5a8d 100644
--- a/packages/ra-ui-materialui/src/form/TabbedForm.js
+++ b/packages/ra-ui-materialui/src/form/TabbedForm.js
@@ -14,6 +14,7 @@ import Divider from '@material-ui/core/Divider';
 import Tabs from '@material-ui/core/Tabs';
 import { withStyles, createStyles } from '@material-ui/core/styles';
 import { getDefaultValues, translate, REDUX_FORM_NAME } from 'ra-core';
+import get from 'lodash/get';
 
 import Toolbar from './Toolbar';
 import CardContentInner from '../layout/CardContentInner';
@@ -271,7 +272,8 @@ export const findTabsWithErrors = (
 
         if (
             inputs.some(
-                input => isValidElement(input) && errors[input.props.source]
+                input =>
+                    isValidElement(input) && get(errors, input.props.source)
             )
         ) {
             return [...acc, child.props.label];
diff --git a/packages/ra-ui-materialui/src/form/TabbedForm.spec.js b/packages/ra-ui-materialui/src/form/TabbedForm.spec.js
index 1ee335025ff..8aec9b0b9b7 100644
--- a/packages/ra-ui-materialui/src/form/TabbedForm.spec.js
+++ b/packages/ra-ui-materialui/src/form/TabbedForm.spec.js
@@ -115,6 +115,9 @@ describe('<TabbedForm />', () => {
             const collectErrors = () => ({
                 field1: 'required',
                 field5: 'required',
+                field7: {
+                    test: 'required',
+                },
             });
             const state = {};
             const props = {
@@ -137,11 +140,17 @@ describe('<TabbedForm />', () => {
                         createElement('input', { source: 'field5' }),
                         createElement('input', { source: 'field6' })
                     ),
+                    createElement(
+                        FormTab,
+                        { label: 'tab4' },
+                        createElement('input', { source: 'field7.test' }),
+                        createElement('input', { source: 'field8' })
+                    ),
                 ],
             };
 
             const tabs = findTabsWithErrors(state, props, collectErrors);
-            assert.deepEqual(tabs, ['tab1', 'tab3']);
+            assert.deepEqual(tabs, ['tab1', 'tab3', 'tab4']);
         });
     });
 });