diff --git a/packages/editor/src/utils/terms.js b/packages/editor/src/utils/terms.js
index 2d34879548a56c..e3154a6480a0fa 100644
--- a/packages/editor/src/utils/terms.js
+++ b/packages/editor/src/utils/terms.js
@@ -14,14 +14,16 @@ export function buildTermsTree( flatTerms ) {
 	const flatTermsWithParentAndChildren = flatTerms.map( ( term ) => {
 		return {
 			children: [],
-			parent: null,
+			parent: undefined,
 			...term,
 		};
 	} );
 
 	// All terms should have a `parent` because we're about to index them by it.
 	if (
-		flatTermsWithParentAndChildren.some( ( { parent } ) => parent === null )
+		flatTermsWithParentAndChildren.some(
+			( { parent } ) => parent === undefined
+		)
 	) {
 		return flatTermsWithParentAndChildren;
 	}
diff --git a/packages/editor/src/utils/test/terms.js b/packages/editor/src/utils/test/terms.js
index 68a1a7f10fb190..fa7d1622370c7a 100644
--- a/packages/editor/src/utils/test/terms.js
+++ b/packages/editor/src/utils/test/terms.js
@@ -4,14 +4,14 @@
 import { buildTermsTree } from '../terms';
 
 describe( 'buildTermsTree()', () => {
-	it( 'Should return same array as input with null parent and empty children added if parent is never specified.', () => {
+	it( 'Should return same array as input with undefined parent and empty children added if parent is never specified.', () => {
 		const input = Object.freeze( [
 			{ id: 2232, dummy: true },
 			{ id: 2245, dummy: true },
 		] );
 		const output = Object.freeze( [
-			{ id: 2232, parent: null, children: [], dummy: true },
-			{ id: 2245, parent: null, children: [], dummy: true },
+			{ id: 2232, parent: undefined, children: [], dummy: true },
+			{ id: 2245, parent: undefined, children: [], dummy: true },
 		] );
 		const termsTreem = buildTermsTree( input );
 		expect( termsTreem ).toEqual( output );