diff --git a/.changeset/calm-houses-carry.md b/.changeset/calm-houses-carry.md
new file mode 100644
index 000000000..4e614e623
--- /dev/null
+++ b/.changeset/calm-houses-carry.md
@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+fix(astro): add support for `src/content/config.mts` files
diff --git a/packages/astro/src/content/utils.ts b/packages/astro/src/content/utils.ts
index 202acd6b9..5834c81d8 100644
--- a/packages/astro/src/content/utils.ts
+++ b/packages/astro/src/content/utils.ts
@@ -448,7 +448,7 @@ export function getContentPaths(
 	};
 }
 function search(fs: typeof fsMod, srcDir: URL) {
-	const paths = ['config.mjs', 'config.js', 'config.ts'].map(
+	const paths = ['config.mjs', 'config.js', 'config.mts', 'config.ts'].map(
 		(p) => new URL(`./content/${p}`, srcDir)
 	);
 	for (const file of paths) {
diff --git a/packages/astro/test/content-collections.test.js b/packages/astro/test/content-collections.test.js
index 10c65b0dd..e39d7da5e 100644
--- a/packages/astro/test/content-collections.test.js
+++ b/packages/astro/test/content-collections.test.js
@@ -214,6 +214,20 @@ describe('Content Collections', () => {
 			expect(error).to.include('**title**: Expected type `"string"`, received "number"');
 		});
 	});
+	describe('With config.mts', () => {
+		it("Errors when frontmatter doesn't match schema", async () => {
+			const fixture = await loadFixture({
+				root: './fixtures/content-collections-with-config-mts/',
+			});
+			let error;
+			try {
+				await fixture.build();
+			} catch (e) {
+				error = e.message;
+			}
+			expect(error).to.include('**title**: Expected type `"string"`, received "number"');
+		});
+	});
 
 	describe('With empty markdown file', () => {
 		it('Throws the right error', async () => {
diff --git a/packages/astro/test/fixtures/content-collections-with-config-mts/package.json b/packages/astro/test/fixtures/content-collections-with-config-mts/package.json
new file mode 100644
index 000000000..cba237161
--- /dev/null
+++ b/packages/astro/test/fixtures/content-collections-with-config-mts/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@test/content-collections-with-config-mts",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/blog/introduction.md b/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/blog/introduction.md
new file mode 100644
index 000000000..c85be69f6
--- /dev/null
+++ b/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/blog/introduction.md
@@ -0,0 +1,5 @@
+---
+title: 10000
+---
+
+# Hi there!
\ No newline at end of file
diff --git a/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/config.mts b/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/config.mts
new file mode 100644
index 000000000..bb2c54aea
--- /dev/null
+++ b/packages/astro/test/fixtures/content-collections-with-config-mts/src/content/config.mts
@@ -0,0 +1,11 @@
+import { z, defineCollection } from 'astro:content';
+
+const blog = defineCollection({
+	schema: z.object({
+		title: z.string(),
+	}),
+});
+
+export const collections = {
+	blog
+}
diff --git a/packages/astro/test/fixtures/content-collections-with-config-mts/src/pages/index.astro b/packages/astro/test/fixtures/content-collections-with-config-mts/src/pages/index.astro
new file mode 100644
index 000000000..4152c0734
--- /dev/null
+++ b/packages/astro/test/fixtures/content-collections-with-config-mts/src/pages/index.astro
@@ -0,0 +1,5 @@
+---
+import {getEntryBySlug} from "astro:content"
+const blogEntry = await getEntryBySlug("blog", "introduction");
+---
+{blogEntry.data.title}
\ No newline at end of file
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8ab3a4d0a..fd844e217 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2373,6 +2373,12 @@ importers:
         specifier: workspace:*
         version: link:../../..
 
+  packages/astro/test/fixtures/content-collections-with-config-mts:
+    dependencies:
+      astro:
+        specifier: workspace:*
+        version: link:../../..
+
   packages/astro/test/fixtures/content-mixed-errors:
     dependencies:
       astro: