diff --git a/types/mithril/index.d.ts b/types/mithril/index.d.ts
index 77ff232f0bd2ff..f9a08ee74de508 100644
--- a/types/mithril/index.d.ts
+++ b/types/mithril/index.d.ts
@@ -9,8 +9,8 @@ declare function mount(element: Element, component: null): void; // tslint:disab
 /** Returns a shallow-cloned object with lifecycle attributes and any given custom attributes omitted. */
 declare function censor<
     O extends Record<string, any>,
-    E extends readonly string[],
->(object: O, extra: E): Omit<Mithril._NoLifecycle<O>, E[number]>;
+    E extends readonly string[] = readonly [],
+>(object: O, extra?: E): Omit<Mithril._NoLifecycle<O>, E[number]>;
 
 /** Makes an XHR request and returns a promise. */
 declare function request<T>(options: Mithril.RequestOptions<T> & { url: string }): Promise<T>;
diff --git a/types/mithril/test/test-misc.ts b/types/mithril/test/test-misc.ts
index 63fb0bae124862..fb32395386bb1d 100644
--- a/types/mithril/test/test-misc.ts
+++ b/types/mithril/test/test-misc.ts
@@ -9,12 +9,22 @@ const params = parseQueryString("?id=123");
 
 const qstr = buildQueryString({ id: 123 });
 
-const censored = censor({ one: "two", enabled: false, oninit: () => {} }, ["enabled"] as const);
-// @ts-expect-error
-censored.enabled;
-// @ts-expect-error
-censored.oninit;
-censored.one;
+{
+    const censored = censor({ one: "two", enabled: false, oninit: () => {} }, ["enabled"] as const);
+    // @ts-expect-error
+    censored.enabled;
+    // @ts-expect-error
+    censored.oninit;
+    censored.one;
+}
+
+{
+    const censored = censor({ one: "two", enabled: false, oninit: () => {} });
+    censored.enabled;
+    // @ts-expect-error
+    censored.oninit;
+    censored.one;
+}
 
 render(document.body, "Hello");
 render(document.body, h("h1", "Test"));