diff --git a/extensions/markdown-language-features/src/extension.ts b/extensions/markdown-language-features/src/extension.ts
index 5312e4109bb..875b5d69f8a 100644
--- a/extensions/markdown-language-features/src/extension.ts
+++ b/extensions/markdown-language-features/src/extension.ts
@@ -17,6 +17,7 @@ import { MarkdownEngine } from './markdownEngine';
 import { getMarkdownExtensionContributions } from './markdownExtensions';
 import { ExtensionContentSecurityPolicyArbiter, PreviewSecuritySelector } from './security';
 import { loadDefaultTelemetryReporter } from './telemetryReporter';
+import { stripSlugifier } from './slugify';
 
 
 export function activate(context: vscode.ExtensionContext) {
@@ -26,7 +27,7 @@ export function activate(context: vscode.ExtensionContext) {
 	const contributions = getMarkdownExtensionContributions();
 
 	const cspArbiter = new ExtensionContentSecurityPolicyArbiter(context.globalState, context.workspaceState);
-	const engine = new MarkdownEngine(contributions);
+	const engine = new MarkdownEngine(contributions, stripSlugifier);
 	const logger = new Logger();
 
 	const selector: vscode.DocumentSelector = [
diff --git a/extensions/markdown-language-features/src/markdownEngine.ts b/extensions/markdown-language-features/src/markdownEngine.ts
index 6d78b575dab..7522eb8b782 100644
--- a/extensions/markdown-language-features/src/markdownEngine.ts
+++ b/extensions/markdown-language-features/src/markdownEngine.ts
@@ -7,7 +7,7 @@ import { MarkdownIt, Token } from 'markdown-it';
 import * as path from 'path';
 import * as vscode from 'vscode';
 import { MarkdownContributions } from './markdownExtensions';
-import { stripSlugifier } from './slugify';
+import { Slugifier } from './slugify';
 
 const FrontMatterRegex = /^---\s*[^]*?(-{3}|\.{3})\s*/;
 
@@ -19,7 +19,8 @@ export class MarkdownEngine {
 	private currentDocument?: vscode.Uri;
 
 	public constructor(
-		private readonly extensionPreviewResourceProvider: MarkdownContributions
+		private readonly extensionPreviewResourceProvider: MarkdownContributions,
+		private readonly slugifier: Slugifier,
 	) { }
 
 	private usePlugin(factory: (md: any) => any): void {
@@ -49,7 +50,7 @@ export class MarkdownEngine {
 					return `<pre class="hljs"><code><div>${this.md!.utils.escapeHtml(str)}</div></code></pre>`;
 				}
 			}).use(mdnh, {
-				slugify: (header: string) => stripSlugifier.fromHeading(header).value
+				slugify: (header: string) => this.slugifier.fromHeading(header).value
 			});
 
 			for (const plugin of this.extensionPreviewResourceProvider.markdownItPlugins) {
@@ -145,13 +146,13 @@ export class MarkdownEngine {
 
 					if (fragment) {
 						uri = uri.with({
-							fragment: stripSlugifier.fromHeading(fragment).value
+							fragment: this.slugifier.fromHeading(fragment).value
 						});
 					}
 					return normalizeLink(uri.with({ scheme: 'vscode-resource' }).toString(true));
 				} else if (!uri.scheme && !uri.path && uri.fragment) {
 					return normalizeLink(uri.with({
-						fragment: stripSlugifier.fromHeading(uri.fragment).value
+						fragment: this.slugifier.fromHeading(uri.fragment).value
 					}).toString(true));
 				}
 			} catch (e) {
diff --git a/extensions/markdown-language-features/src/test/engine.ts b/extensions/markdown-language-features/src/test/engine.ts
index a7a30a89ce0..fbd2322cc38 100644
--- a/extensions/markdown-language-features/src/test/engine.ts
+++ b/extensions/markdown-language-features/src/test/engine.ts
@@ -6,13 +6,15 @@
 import * as vscode from 'vscode';
 import { MarkdownEngine } from '../markdownEngine';
 import { MarkdownContributions } from '../markdownExtensions';
+import { stripSlugifier } from '../slugify';
+
+const emptyContributions = new class implements MarkdownContributions {
+	readonly previewScripts: vscode.Uri[] = [];
+	readonly previewStyles: vscode.Uri[] = [];
+	readonly previewResourceRoots: vscode.Uri[] = [];
+	readonly markdownItPlugins: Promise<(md: any) => any>[] = [];
+};
 
 export function createNewMarkdownEngine(): MarkdownEngine {
-	return new MarkdownEngine(new class implements MarkdownContributions {
-		readonly previewScripts: vscode.Uri[] = [];
-		readonly previewStyles: vscode.Uri[] = [];
-		readonly previewResourceRoots: vscode.Uri[] = [];
-		readonly markdownItPlugins: Promise<(md: any) => any>[] = [];
-	});
+	return new MarkdownEngine(emptyContributions, stripSlugifier);
 }
-