diff --git a/packages/edit-site/lib/unbrotli.js b/packages/edit-site/lib/unbrotli.js
index 0560b35622c209..63293e6cc473cf 100644
--- a/packages/edit-site/lib/unbrotli.js
+++ b/packages/edit-site/lib/unbrotli.js
@@ -1703,19 +1703,11 @@ function fromByteArray (uint8) {
    decoding of the block lengths, literal insertion lengths and copy lengths.
 */
 
-/**
- * Represents the range of values belonging to a prefix code.
- * [offset, offset + 2^nbits)
- *
- * @param {number} offset The starting offset of the range.
- * @param {number} nbits  The number of bits defining the range.
- * @constructor
- */
-class PrefixCodeRange {
-  constructor( offset, nbits ) {
-    this.offset = offset;
-    this.nbits = nbits;
-  }
+/* Represents the range of values belonging to a prefix code: */
+/* [offset, offset + 2^nbits) */
+function PrefixCodeRange(offset, nbits) {
+  this.offset = offset;
+  this.nbits = nbits;
 }
 
 exports.kBlockLengthPrefixCode = [
@@ -1832,26 +1824,16 @@ var kOmitFirst7     = 18;
 var kOmitFirst8     = 19;
 var kOmitFirst9     = 20;
 
-/**
- * Represents a transformation with a prefix, a transform type, and a suffix.
- *
- * @param {string} prefix - The prefix string.
- * @param {number} transform - The transform type.
- * @param {string} suffix - The suffix string.
- * @constructor
- */
-class Transform {
-  constructor( prefix, transform, suffix ) {
-    this.prefix = new Uint8Array( prefix.length );
-    this.transform = transform;
-    this.suffix = new Uint8Array(suffix.length);
+function Transform(prefix, transform, suffix) {
+  this.prefix = new Uint8Array(prefix.length);
+  this.transform = transform;
+  this.suffix = new Uint8Array(suffix.length);
 
-    for ( var i = 0; i < prefix.length; i++ )
-      this.prefix[i] = prefix.charCodeAt( i );
+  for (var i = 0; i < prefix.length; i++)
+    this.prefix[i] = prefix.charCodeAt(i);
 
-    for ( var i = 0; i < suffix.length; i++ )
-      this.suffix[i] = suffix.charCodeAt( i );
-  }
+  for (var i = 0; i < suffix.length; i++)
+    this.suffix[i] = suffix.charCodeAt(i);
 }
 
 var kTransforms = [
diff --git a/packages/edit-site/src/components/global-styles/font-library-modal/upload-fonts.js b/packages/edit-site/src/components/global-styles/font-library-modal/upload-fonts.js
index 807f2aa354c25a..c918f5d795654d 100644
--- a/packages/edit-site/src/components/global-styles/font-library-modal/upload-fonts.js
+++ b/packages/edit-site/src/components/global-styles/font-library-modal/upload-fonts.js
@@ -20,6 +20,7 @@ import { useContext, useState } from '@wordpress/element';
  */
 import { ALLOWED_FILE_EXTENSIONS } from './utils/constants';
 import { FontLibraryContext } from './context';
+// @ts-ignore
 import { Font } from '../../../../lib/lib-font.browser';
 import makeFamiliesFromFaces from './utils/make-families-from-faces';
 import { loadFontFaceInBrowser } from './utils';