diff --git a/.changeset/happy-snails-ring.md b/.changeset/happy-snails-ring.md
new file mode 100644
index 000000000..adab2967b
--- /dev/null
+++ b/.changeset/happy-snails-ring.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/rss': patch
+---
+
+Fixes `RSSOptions` type error when using `strictest` Typescript tsconfig
diff --git a/packages/astro-rss/src/index.ts b/packages/astro-rss/src/index.ts
index 7764b5d13..9c5908b93 100644
--- a/packages/astro-rss/src/index.ts
+++ b/packages/astro-rss/src/index.ts
@@ -36,7 +36,7 @@ type RSSFeedItem = {
 	/** Link to item */
 	link: string;
 	/** Full content of the item. Should be valid HTML */
-	content?: string;
+	content?: string | undefined;
 	/** Title of item */
 	title: z.infer<typeof rssSchema>['title'];
 	/** Publication date of item */