diff --git a/ts/html-filter/index.test.ts b/ts/html-filter/index.test.ts
index 35d33bb3b..c3e2a724b 100644
--- a/ts/html-filter/index.test.ts
+++ b/ts/html-filter/index.test.ts
@@ -1,6 +1,12 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-test("it should work", () => {
-    expect("test").toBe("test");
+import { filterHTML } from ".";
+
+describe("filterHTML", () => {
+    test("zero input creates zero output", () => {
+        expect(filterHTML("", true, false)).toBe("");
+        expect(filterHTML("", true, false)).toBe("");
+        expect(filterHTML("", false, false)).toBe("");
+    });
 });