diff --git a/plugins/woocommerce-blocks/assets/js/atomic/utils/register-block-single-product-template.ts b/plugins/woocommerce-blocks/assets/js/atomic/utils/register-block-single-product-template.ts
index d1e853acbe9..5d7e1ab020f 100644
--- a/plugins/woocommerce-blocks/assets/js/atomic/utils/register-block-single-product-template.ts
+++ b/plugins/woocommerce-blocks/assets/js/atomic/utils/register-block-single-product-template.ts
@@ -1,6 +1,7 @@
 /**
  * External dependencies
  */
+import { isNumber } from '@woocommerce/types';
 import {
 	BlockAttributes,
 	BlockConfiguration,
@@ -16,8 +17,10 @@ import { subscribe, select } from '@wordpress/data';
 // Creating a local cache to prevent multiple registration tries.
 const blocksRegistered = new Set();
 
-function parseTemplateId( templateId: string | undefined ) {
-	return templateId?.split( '//' )[ 1 ];
+function parseTemplateId( templateId: string | number | undefined ) {
+	// With GB 16.3.0 the return type can be a number: https://github.com/WordPress/gutenberg/issues/53230
+	const parsedTemplateId = isNumber( templateId ) ? undefined : templateId;
+	return parsedTemplateId?.split( '//' )[ 1 ];
 }
 
 export const registerBlockSingleProductTemplate = ( {
@@ -40,7 +43,11 @@ export const registerBlockSingleProductTemplate = ( {
 	subscribe( () => {
 		const previousTemplateId = currentTemplateId;
 		const store = select( 'core/edit-site' );
-		currentTemplateId = parseTemplateId( store?.getEditedPostId() );
+
+		// With GB 16.3.0 the return type can be a number: https://github.com/WordPress/gutenberg/issues/53230
+		currentTemplateId = parseTemplateId(
+			store?.getEditedPostId() as string | number | undefined
+		);
 		const hasChangedTemplate = previousTemplateId !== currentTemplateId;
 		const hasTemplateId = Boolean( currentTemplateId );
 
diff --git a/plugins/woocommerce-blocks/assets/js/blocks/classic-template/index.tsx b/plugins/woocommerce-blocks/assets/js/blocks/classic-template/index.tsx
index 9d69c00c2b3..7f89427e0a0 100644
--- a/plugins/woocommerce-blocks/assets/js/blocks/classic-template/index.tsx
+++ b/plugins/woocommerce-blocks/assets/js/blocks/classic-template/index.tsx
@@ -31,6 +31,7 @@ import { store as noticesStore } from '@wordpress/notices';
 import { useEntityRecord } from '@wordpress/core-data';
 import { debounce } from '@woocommerce/base-utils';
 import { woo } from '@woocommerce/icons';
+import { isNumber } from '@woocommerce/types';
 
 /**
  * Internal dependencies
@@ -417,7 +418,14 @@ let currentTemplateId: string | undefined;
 subscribe( () => {
 	const previousTemplateId = currentTemplateId;
 	const store = select( 'core/edit-site' );
-	currentTemplateId = store?.getEditedPostId() as string | undefined;
+	// With GB 16.3.0 the return type can be a number: https://github.com/WordPress/gutenberg/issues/53230
+	const editedPostId = store?.getEditedPostId() as
+		| string
+		| number
+		| undefined;
+
+	currentTemplateId = isNumber( editedPostId ) ? undefined : editedPostId;
+
 	const parsedTemplate = currentTemplateId?.split( '//' )[ 1 ];
 
 	if ( parsedTemplate === null || parsedTemplate === undefined ) {