diff --git a/packages/lit-dev-content/site/docs/v2/templates/directives.md b/packages/lit-dev-content/site/docs/v2/templates/directives.md
index 5149c8eb5..b77ade4cd 100644
--- a/packages/lit-dev-content/site/docs/v2/templates/directives.md
+++ b/packages/lit-dev-content/site/docs/v2/templates/directives.md
@@ -1831,7 +1831,10 @@ import {asyncAppend} from 'lit/directives/async-append.js';
 <td class="wide-cell">
 
 ```ts
-asyncAppend(iterable: AsyncIterable, mapper?: Function)
+asyncAppend(
+  iterable: AsyncIterable,
+  mapper?: (item: Item, index?: number) => unknown
+)
 ```
 
 </td>
@@ -1924,7 +1927,10 @@ import {asyncReplace} from 'lit/directives/async-replace.js';
 <td class="wide-cell">
 
 ```ts
-asyncReplace(iterable: AsyncIterable, mapper?: Function)
+asyncReplace(
+  iterable: AsyncIterable,
+  mapper?: (item: Item, index?: number) => unknown
+)
 ```
 
 </td>
diff --git a/packages/lit-dev-content/site/docs/v3/templates/directives.md b/packages/lit-dev-content/site/docs/v3/templates/directives.md
index 30ba52ee2..45f9d4920 100644
--- a/packages/lit-dev-content/site/docs/v3/templates/directives.md
+++ b/packages/lit-dev-content/site/docs/v3/templates/directives.md
@@ -1831,7 +1831,10 @@ import {asyncAppend} from 'lit/directives/async-append.js';
 <td class="wide-cell">
 
 ```ts
-asyncAppend(iterable: AsyncIterable, mapper?: Function)
+asyncAppend(
+  iterable: AsyncIterable,
+  mapper?: (item: Item, index?: number) => unknown
+)
 ```
 
 </td>
@@ -1924,7 +1927,10 @@ import {asyncReplace} from 'lit/directives/async-replace.js';
 <td class="wide-cell">
 
 ```ts
-asyncReplace(iterable: AsyncIterable, mapper?: Function)
+asyncReplace(
+  iterable: AsyncIterable,
+  mapper?: (item: Item, index?: number) => unknown
+)
 ```
 
 </td>