diff --git a/packages/block-library/src/image/transforms.js b/packages/block-library/src/image/transforms.js
index 32824c372efdcb..0119009b2182c4 100644
--- a/packages/block-library/src/image/transforms.js
+++ b/packages/block-library/src/image/transforms.js
@@ -59,7 +59,7 @@ const schema = ( { phrasingContentSchema } ) => ( {
 			...imageSchema,
 			a: {
 				attributes: [ 'href', 'rel', 'target' ],
-				classes: [ /[\w-]*/ ],
+				classes: [ '*' ],
 				children: imageSchema,
 			},
 			figcaption: {
diff --git a/packages/dom/src/dom/clean-node-list.js b/packages/dom/src/dom/clean-node-list.js
index bbdff13b470d69..f1b7e1be7264f4 100644
--- a/packages/dom/src/dom/clean-node-list.js
+++ b/packages/dom/src/dom/clean-node-list.js
@@ -76,7 +76,10 @@ export default function cleanNodeList( nodeList, doc, schema, inline ) {
 						// TODO: Explore patching this in jsdom-jscore.
 						if ( node.classList && node.classList.length ) {
 							const mattchers = classes.map( ( item ) => {
-								if ( typeof item === 'string' ) {
+								if ( item === '*' ) {
+									// Keep all classes.
+									return () => true;
+								} else if ( typeof item === 'string' ) {
 									return (
 										/** @type {string} */ className
 									) => className === item;