diff --git a/.eslintignore b/.eslintignore
index 29dae636a..9d5e0376e 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -103,6 +103,9 @@ packages/app-cli/tests/Synchronizer.tags.js.map
 packages/app-cli/tests/fsDriver.d.ts
 packages/app-cli/tests/fsDriver.js
 packages/app-cli/tests/fsDriver.js.map
+packages/app-cli/tests/htmlUtils.d.ts
+packages/app-cli/tests/htmlUtils.js
+packages/app-cli/tests/htmlUtils.js.map
 packages/app-cli/tests/models_Folder.d.ts
 packages/app-cli/tests/models_Folder.js
 packages/app-cli/tests/models_Folder.js.map
diff --git a/.gitignore b/.gitignore
index 85cc14303..66e964c79 100644
--- a/.gitignore
+++ b/.gitignore
@@ -90,6 +90,9 @@ packages/app-cli/tests/Synchronizer.tags.js.map
 packages/app-cli/tests/fsDriver.d.ts
 packages/app-cli/tests/fsDriver.js
 packages/app-cli/tests/fsDriver.js.map
+packages/app-cli/tests/htmlUtils.d.ts
+packages/app-cli/tests/htmlUtils.js
+packages/app-cli/tests/htmlUtils.js.map
 packages/app-cli/tests/models_Folder.d.ts
 packages/app-cli/tests/models_Folder.js
 packages/app-cli/tests/models_Folder.js.map
diff --git a/packages/app-cli/tests/htmlUtils.js b/packages/app-cli/tests/htmlUtils.ts
similarity index 88%
rename from packages/app-cli/tests/htmlUtils.js
rename to packages/app-cli/tests/htmlUtils.ts
index 70c2d3ef8..bbe69af9b 100644
--- a/packages/app-cli/tests/htmlUtils.js
+++ b/packages/app-cli/tests/htmlUtils.ts
@@ -1,6 +1,4 @@
-/* eslint-disable no-unused-vars */
-
-const htmlUtils = require('@joplin/lib/htmlUtils.js');
+import htmlUtils from '@joplin/lib/htmlUtils';
 
 describe('htmlUtils', function() {
 
@@ -19,8 +17,8 @@ describe('htmlUtils', function() {
 		];
 
 		for (let i = 0; i < testCases.length; i++) {
-			const md = testCases[i][0];
-			const expected = testCases[i][1];
+			const md = testCases[i][0] as string;
+			const expected = testCases[i][1] as string[];
 
 			expect(htmlUtils.extractImageUrls(md).join(' ')).toBe(expected.join(' '));
 		}
@@ -33,19 +31,19 @@ describe('htmlUtils', function() {
 			['<img src="http://test.com/img.png" alt="testing"  >', ['http://other.com/img.png'], '<img src="http://other.com/img.png" alt="testing"  >'],
 		];
 
-		const callback = (urls) => {
+		const callback = (urls: string[]) => {
 			let i = -1;
 
-			return function(src) {
+			return function(_src: string) {
 				i++;
 				return urls[i];
 			};
 		};
 
 		for (let i = 0; i < testCases.length; i++) {
-			const md = testCases[i][0];
-			const r = htmlUtils.replaceImageUrls(md, callback(testCases[i][1]));
-			expect(r.trim()).toBe(testCases[i][2].trim());
+			const md = testCases[i][0] as string;
+			const r = htmlUtils.replaceImageUrls(md, callback(testCases[i][1] as string[]));
+			expect(r.trim()).toBe((testCases[i][2] as string).trim());
 		}
 	}));
 
diff --git a/packages/lib/htmlUtils.ts b/packages/lib/htmlUtils.ts
index ffce08a4b..6dd03e400 100644
--- a/packages/lib/htmlUtils.ts
+++ b/packages/lib/htmlUtils.ts
@@ -31,19 +31,20 @@ const selfClosingElements = [
 ];
 
 class HtmlUtils {
-	headAndBodyHtml(doc: any) {
+
+	public headAndBodyHtml(doc: any) {
 		const output = [];
 		if (doc.head) output.push(doc.head.innerHTML);
 		if (doc.body) output.push(doc.body.innerHTML);
 		return output.join('\n');
 	}
 
-	isSelfClosingTag(tagName: string) {
+	public isSelfClosingTag(tagName: string) {
 		return selfClosingElements.includes(tagName.toLowerCase());
 	}
 
 	// Returns the **encoded** URLs, so to be useful they should be decoded again before use.
-	extractImageUrls(html: string) {
+	public extractImageUrls(html: string) {
 		if (!html) return [];
 
 		const output = [];
@@ -55,7 +56,7 @@ class HtmlUtils {
 		return output.filter(url => !!url);
 	}
 
-	replaceImageUrls(html: string, callback: Function) {
+	public replaceImageUrls(html: string, callback: Function) {
 		return this.processImageTags(html, (data: any) => {
 			const newSrc = callback(data.src);
 			return {
@@ -65,7 +66,7 @@ class HtmlUtils {
 		});
 	}
 
-	processImageTags(html: string, callback: Function) {
+	public processImageTags(html: string, callback: Function) {
 		if (!html) return '';
 
 		return html.replace(imageRegex, (_v: string, before: string, src: string, after: string) => {
@@ -90,7 +91,7 @@ class HtmlUtils {
 		});
 	}
 
-	prependBaseUrl(html: string, baseUrl: string) {
+	public prependBaseUrl(html: string, baseUrl: string) {
 		if (!html) return '';
 
 		return html.replace(anchorRegex, (_v: string, before: string, href: string, after: string) => {
@@ -99,7 +100,7 @@ class HtmlUtils {
 		});
 	}
 
-	attributesHtml(attr: any) {
+	public attributesHtml(attr: any) {
 		const output = [];
 
 		for (const n in attr) {
@@ -110,7 +111,7 @@ class HtmlUtils {
 		return output.join(' ');
 	}
 
-	stripHtml(html: string) {
+	public stripHtml(html: string) {
 		const output: string[] = [];
 
 		const tagStack: any[] = [];