code · pull · Jan 23, 2026 · Jan 23, 2026 · Jan 23, 2026
diff --git a/examples/basics/package.json b/examples/basics/package.json
@@ -10,6 +10,6 @@
     "astro": "astro"
   },
   "dependencies": {
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/blog/package.json b/examples/blog/package.json
@@ -13,7 +13,7 @@
     "@astrojs/mdx": "^4.3.13",
     "@astrojs/rss": "^4.0.15",
     "@astrojs/sitemap": "^3.7.0",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "sharp": "^0.34.3"
   }
 }
diff --git a/examples/component/package.json b/examples/component/package.json
@@ -15,7 +15,7 @@
   ],
   "scripts": {},
   "devDependencies": {
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   },
   "peerDependencies": {
     "astro": "^4.0.0 || ^5.0.0"

diff --git a/examples/container-with-vitest/package.json b/examples/container-with-vitest/package.json
@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "@astrojs/react": "^4.4.2",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
     "vitest": "^3.2.4"

diff --git a/examples/framework-alpine/package.json b/examples/framework-alpine/package.json
@@ -13,6 +13,6 @@
     "@astrojs/alpinejs": "^0.4.9",
     "@types/alpinejs": "^3.13.11",
     "alpinejs": "^3.15.4",
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/framework-multiple/package.json b/examples/framework-multiple/package.json
@@ -17,7 +17,7 @@
     "@astrojs/vue": "^5.1.4",
     "@types/react": "^18.3.27",
     "@types/react-dom": "^18.3.7",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "preact": "^10.28.2",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",

diff --git a/examples/framework-preact/package.json b/examples/framework-preact/package.json
@@ -12,7 +12,7 @@
   "dependencies": {
     "@astrojs/preact": "^4.1.3",
     "@preact/signals": "^2.5.1",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "preact": "^10.28.2"
   }
 }
diff --git a/examples/framework-react/package.json b/examples/framework-react/package.json
@@ -13,7 +13,7 @@
     "@astrojs/react": "^4.4.2",
     "@types/react": "^18.3.27",
     "@types/react-dom": "^18.3.7",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"
   }

diff --git a/examples/framework-solid/package.json b/examples/framework-solid/package.json
@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@astrojs/solid-js": "^5.1.3",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "solid-js": "^1.9.10"
   }
 }
diff --git a/examples/framework-svelte/package.json b/examples/framework-svelte/package.json
@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@astrojs/svelte": "^7.2.5",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "svelte": "^5.46.1"
   }
 }
diff --git a/examples/framework-vue/package.json b/examples/framework-vue/package.json
@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@astrojs/vue": "^5.1.4",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "vue": "^3.5.26"
   }
 }
diff --git a/examples/hackernews/package.json b/examples/hackernews/package.json
@@ -11,6 +11,6 @@
   },
   "dependencies": {
     "@astrojs/node": "^9.5.2",
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/integration/package.json b/examples/integration/package.json
@@ -15,7 +15,7 @@
   ],
   "scripts": {},
   "devDependencies": {
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   },
   "peerDependencies": {
     "astro": "^4.0.0"

diff --git a/examples/minimal/package.json b/examples/minimal/package.json
@@ -10,6 +10,6 @@
     "astro": "astro"
   },
   "dependencies": {
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/portfolio/package.json b/examples/portfolio/package.json
@@ -10,6 +10,6 @@
     "astro": "astro"
   },
   "dependencies": {
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/ssr/package.json b/examples/ssr/package.json
@@ -13,7 +13,7 @@
   "dependencies": {
     "@astrojs/node": "^9.5.2",
     "@astrojs/svelte": "^7.2.5",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "svelte": "^5.46.1"
   }
 }
diff --git a/examples/starlog/package.json b/examples/starlog/package.json
@@ -9,7 +9,7 @@
     "astro": "astro"
   },
   "dependencies": {
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "sass": "^1.97.2",
     "sharp": "^0.34.3"
   }

diff --git a/examples/toolbar-app/package.json b/examples/toolbar-app/package.json
@@ -16,6 +16,6 @@
   },
   "devDependencies": {
     "@types/node": "^18.17.8",
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/with-markdoc/package.json b/examples/with-markdoc/package.json
@@ -11,6 +11,6 @@
   },
   "dependencies": {
     "@astrojs/markdoc": "^0.15.10",
-    "astro": "^5.16.14"
+    "astro": "^5.16.15"
   }
 }
diff --git a/examples/with-mdx/package.json b/examples/with-mdx/package.json
@@ -12,7 +12,7 @@
   "dependencies": {
     "@astrojs/mdx": "^4.3.13",
     "@astrojs/preact": "^4.1.3",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "preact": "^10.28.2"
   }
 }
diff --git a/examples/with-nanostores/package.json b/examples/with-nanostores/package.json
@@ -12,7 +12,7 @@
   "dependencies": {
     "@astrojs/preact": "^4.1.3",
     "@nanostores/preact": "^0.5.2",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "nanostores": "^0.11.4",
     "preact": "^10.28.2"
   }

diff --git a/examples/with-tailwindcss/package.json b/examples/with-tailwindcss/package.json
@@ -13,7 +13,7 @@
     "@astrojs/mdx": "^4.3.13",
     "@tailwindcss/vite": "^4.1.18",
     "@types/canvas-confetti": "^1.9.0",
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "canvas-confetti": "^1.9.4",
     "tailwindcss": "^4.1.18"
   }

diff --git a/examples/with-vitest/package.json b/examples/with-vitest/package.json
@@ -11,7 +11,7 @@
     "test": "vitest"
   },
   "dependencies": {
-    "astro": "^5.16.14",
+    "astro": "^5.16.15",
     "vitest": "^3.2.4"
   }
 }
diff --git a/packages/astro/CHANGELOG.md b/packages/astro/CHANGELOG.md
@@ -1,5 +1,11 @@
 # astro
 
+## 5.16.15
+
+### Patch Changes
+
+- [#15286](https://github.com/withastro/astro/pull/15286) [`0aafc83`](https://github.com/withastro/astro/commit/0aafc8342a47f5c96cd13bfc02539d89c3c358a7) Thanks [@florian-lefebvre](https://github.com/florian-lefebvre)! - Fixes a case where font providers provided as class instances may not work when using the experimental Fonts API. It affected the local provider
+
 ## 5.16.14
 
 ### Patch Changes

diff --git a/packages/astro/package.json b/packages/astro/package.json
@@ -1,6 +1,6 @@
 {
   "name": "astro",
-  "version": "5.16.14",
+  "version": "5.16.15",
   "description": "Astro is a modern site builder with web best practices, performance, and DX front-of-mind.",
   "type": "module",
   "author": "withastro",

diff --git a/packages/astro/src/assets/fonts/config.ts b/packages/astro/src/assets/fonts/config.ts
@@ -26,7 +26,7 @@ const requiredFamilyAttributesSchema = z.object({
 	cssVariable: z.string(),
 });
 
-export const fontProviderSchema = z
+const _fontProviderSchema = z
 	.object({
 		name: z.string(),
 		config: z.record(z.string(), z.any()).optional(),
@@ -36,6 +36,13 @@ export const fontProviderSchema = z
 	})
 	.strict();
 
+// Using z.object directly makes zod remap the input, preventing
+// the usage of class instances. Instead, we check if it matches
+// the right shape and pass the original
+export const fontProviderSchema = z.custom<FontProvider>((v) => {
+	return _fontProviderSchema.safeParse(v).success;
+}, 'Invalid FontProvider object');
+
 export const fontFamilySchema = z
 	.object({
 		...requiredFamilyAttributesSchema.shape,

diff --git a/packages/astro/test/units/config/config-validate.test.js b/packages/astro/test/units/config/config-validate.test.js
@@ -4,6 +4,7 @@ import { describe, it } from 'node:test';
 import { stripVTControlCharacters } from 'node:util';
 import { z } from 'zod';
 import { fontProviders } from '../../../dist/assets/fonts/providers/index.js';
+import { LocalFontProvider } from '../../../dist/assets/fonts/providers/local.js';
 import { validateConfig as _validateConfig } from '../../../dist/core/config/validate.js';
 import { formatConfigErrorMessage } from '../../../dist/core/messages.js';
 import { envField } from '../../../dist/env/config.js';
@@ -534,6 +535,22 @@ describe('Config Validation', () => {
 				}),
 			);
 		});
+
+		it('should preserve FontProvider as a class instance', async () => {
+			const config = await validateConfig({
+				experimental: {
+					fonts: [
+						{
+							provider: fontProviders.local(),
+							name: 'Roboto',
+							cssVariable: '--font-roboto',
+							options: {},
+						},
+					],
+				},
+			});
+			assert.equal(config.experimental.fonts?.[0].provider instanceof LocalFontProvider, true);
+		});
 	});
 
 	describe('csp', () => {