diff --git a/packages/e2e-tests/specs/editor/various/font-size-picker.test.js b/packages/e2e-tests/specs/editor/various/font-size-picker.test.js
index bb740cae8981c5..f7351450dabd51 100644
--- a/packages/e2e-tests/specs/editor/various/font-size-picker.test.js
+++ b/packages/e2e-tests/specs/editor/various/font-size-picker.test.js
@@ -102,51 +102,59 @@ describe( 'Font Size Picker', () => {
 	describe( 'More font sizes', () => {
 		beforeEach( async () => {
 			await page.evaluate( () => {
+				// set a deep `path[]` property in object `obj` to `value`, immutably
+				function setDeep( obj, path, value ) {
+					function doSet( o, i ) {
+						if ( i < path.length ) {
+							const key = path[ i ];
+							return { ...o, [ key ]: doSet( o[ key ], i + 1 ) };
+						}
+						return value;
+					}
+					return doSet( obj, 0 );
+				}
+
 				wp.data.dispatch( 'core/block-editor' ).updateSettings(
-					// eslint-disable-next-line no-undef
-					lodash.merge(
+					setDeep(
 						wp.data.select( 'core/block-editor' ).getSettings(),
-						{
-							__experimentalFeatures: {
-								typography: {
-									fontSizes: {
-										default: [
-											{
-												name: 'Tiny',
-												slug: 'tiny',
-												size: '11px',
-											},
-											,
-											{
-												name: 'Small',
-												slug: 'small',
-												size: '13px',
-											},
-											{
-												name: 'Medium',
-												slug: 'medium',
-												size: '20px',
-											},
-											{
-												name: 'Large',
-												slug: 'large',
-												size: '36px',
-											},
-											{
-												name: 'Extra Large',
-												slug: 'x-large',
-												size: '42px',
-											},
-											{
-												name: 'Huge',
-												slug: 'huge',
-												size: '48px',
-											},
-										],
-									},
-								},
+						[
+							'__experimentalFeatures',
+							'typography',
+							'fontSizes',
+							'default',
+						],
+						[
+							{
+								name: 'Tiny',
+								slug: 'tiny',
+								size: '11px',
 							},
-						}
+							{
+								name: 'Small',
+								slug: 'small',
+								size: '13px',
+							},
+							{
+								name: 'Medium',
+								slug: 'medium',
+								size: '20px',
+							},
+							{
+								name: 'Large',
+								slug: 'large',
+								size: '36px',
+							},
+							{
+								name: 'Extra Large',
+								slug: 'x-large',
+								size: '42px',
+							},
+							{
+								name: 'Huge',
+								slug: 'huge',
+								size: '48px',
+							},
+						]
 					)
 				);
 			} );
@@ -158,7 +166,7 @@ describe( 'Font Size Picker', () => {
 			await page.keyboard.type( 'Paragraph to be made "large"' );
 
 			await openFontSizeSelectControl();
-			await pressKeyTimes( 'ArrowDown', 5 );
+			await pressKeyTimes( 'ArrowDown', 4 );
 			await page.keyboard.press( 'Enter' );
 
 			expect( await getEditedPostContent() ).toMatchInlineSnapshot( `
@@ -175,7 +183,7 @@ describe( 'Font Size Picker', () => {
 			);
 
 			await openFontSizeSelectControl();
-			await pressKeyTimes( 'ArrowDown', 4 );
+			await pressKeyTimes( 'ArrowDown', 3 );
 			await page.keyboard.press( 'Enter' );
 			expect( await getEditedPostContent() ).toMatchInlineSnapshot( `
 			"<!-- wp:paragraph {\\"fontSize\\":\\"medium\\"} -->
@@ -202,7 +210,7 @@ describe( 'Font Size Picker', () => {
 			);
 
 			await openFontSizeSelectControl();
-			await pressKeyTimes( 'ArrowDown', 3 );
+			await pressKeyTimes( 'ArrowDown', 2 );
 			await page.keyboard.press( 'Enter' );
 			expect( await getEditedPostContent() ).toMatchInlineSnapshot( `
 			"<!-- wp:paragraph {\\"fontSize\\":\\"small\\"} -->