diff --git a/.changeset/green-ducks-reply.md b/.changeset/green-ducks-reply.md
new file mode 100644
index 000000000..20b00ddca
--- /dev/null
+++ b/.changeset/green-ducks-reply.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes imported CSS packages in frontmatter
diff --git a/packages/astro/package.json b/packages/astro/package.json
index 24fb9ac06..4a611ac0e 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -130,7 +130,7 @@
     "strip-ansi": "^7.0.1",
     "supports-esm": "^1.0.0",
     "tsconfig-resolver": "^3.0.1",
-    "vite": "^2.9.9",
+    "vite": "^2.9.10",
     "yargs-parser": "^21.0.1",
     "zod": "^3.17.3"
   },
diff --git a/packages/astro/src/vite-plugin-build-css/index.ts b/packages/astro/src/vite-plugin-build-css/index.ts
index a38ffc731..6656d350e 100644
--- a/packages/astro/src/vite-plugin-build-css/index.ts
+++ b/packages/astro/src/vite-plugin-build-css/index.ts
@@ -1,4 +1,4 @@
-import type { GetModuleInfo, ModuleInfo } from 'rollup';
+import type { GetModuleInfo, ModuleInfo, OutputChunk } from 'rollup';
 import { BuildInternals } from '../core/build/internal';
 import type { PageBuildData } from '../core/build/types';
 
@@ -76,25 +76,6 @@ export function rollupPluginAstroBuildCSS(options: PluginOptions): VitePlugin[]
 		{
 			name: CSS_PLUGIN_NAME,
 
-			configResolved(resolvedConfig) {
-				// Our plugin needs to run before `vite:css-post` because we have to modify
-				// The bundles before vite:css-post sees them. We can remove this code
-				// after this bug is fixed: https://github.com/vitejs/vite/issues/8330
-				const plugins = resolvedConfig.plugins as VitePlugin[];
-				const viteCSSPostIndex = resolvedConfig.plugins.findIndex(
-					(p) => p.name === 'vite:css-post'
-				);
-				if (viteCSSPostIndex !== -1) {
-					// Move our plugin to be right before this one.
-					const ourIndex = plugins.findIndex((p) => p.name === CSS_PLUGIN_NAME);
-					const ourPlugin = plugins[ourIndex];
-
-					// Remove us from where we are now and place us right before the viteCSSPost plugin
-					plugins.splice(ourIndex, 1);
-					plugins.splice(viteCSSPostIndex - 1, 0, ourPlugin);
-				}
-			},
-
 			outputOptions(outputOptions) {
 				const manualChunks = outputOptions.manualChunks || Function.prototype;
 				outputOptions.manualChunks = function (id, ...args) {
@@ -157,21 +138,8 @@ export function rollupPluginAstroBuildCSS(options: PluginOptions): VitePlugin[]
 							}
 						}
 					}
-
-					if (chunk.type === 'chunk') {
-						// This simply replaces single quotes with double quotes because the vite:css-post
-						// plugin only works with single for some reason. This code can be removed
-						// When the Vite bug is fixed: https://github.com/vitejs/vite/issues/8330
-						const exp = new RegExp(
-							`(\\bimport\\s*)[']([^']*(?:[a-z]+\.[0-9a-z]+\.m?js))['](;\n?)`,
-							'g'
-						);
-						chunk.code = chunk.code.replace(exp, (_match, begin, chunkPath, end) => {
-							return begin + '"' + chunkPath + '"' + end;
-						});
-					}
 				}
-			},
+			}
 		},
 		{
 			name: CSS_MINIFY_PLUGIN_NAME,
@@ -190,10 +158,40 @@ export function rollupPluginAstroBuildCSS(options: PluginOptions): VitePlugin[]
 								});
 								output.source = minifiedCSS;
 							}
+						} else if (output.type === 'chunk') {
+							// vite:css-post removes "pure CSS" JavaScript chunks, that is chunks that only contain a comment
+							// about it being a CSS module. We need to keep these chunks around because Astro
+							// re-imports all modules as their namespace `import * as module1 from 'some/path';
+							// in order to determine if one of them is a side-effectual web component.
+							// If we ever get rid of that feature, the code below can be removed.
+							for(const [imp, bindings] of Object.entries(output.importedBindings)) {
+								if(imp.startsWith('chunks/') && !bundle[imp] && output.code.includes(imp)) {
+									// This just creates an empty chunk module so that the main entry module
+									// that is importing it doesn't break.
+									const depChunk: OutputChunk = {
+										type: 'chunk',
+										fileName: imp,
+										name: imp,
+										facadeModuleId: imp,
+										code: `/* Pure CSS chunk ${imp} */ ${bindings.map(b => `export const ${b} = {};`)}`,
+										dynamicImports: [],
+										implicitlyLoadedBefore: [],
+										importedBindings: {},
+										imports: [],
+										referencedFiles: [],
+										exports: Array.from(bindings),
+										isDynamicEntry: false,
+										isEntry: false,
+										isImplicitEntry: false,
+										modules: {},
+									};
+									bundle[imp] = depChunk;
+								}
+							}
 						}
 					}
 				}
-			},
-		},
+			}
+		}
 	];
 }
diff --git a/packages/astro/test/fixtures/fontsource-package/package.json b/packages/astro/test/fixtures/fontsource-package/package.json
new file mode 100644
index 000000000..2056d8447
--- /dev/null
+++ b/packages/astro/test/fixtures/fontsource-package/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@test/astro-fontsource-package",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@fontsource/montserrat": "4.5.11",
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/astro/test/fixtures/fontsource-package/src/pages/index.astro b/packages/astro/test/fixtures/fontsource-package/src/pages/index.astro
new file mode 100644
index 000000000..9c57bf10d
--- /dev/null
+++ b/packages/astro/test/fixtures/fontsource-package/src/pages/index.astro
@@ -0,0 +1,13 @@
+---
+import "@fontsource/montserrat";
+---
+<html lang="en">
+	<head>
+		<meta charset="utf-8" />
+		<meta name="viewport" content="width=device-width" />
+		<title>Astro</title>
+	</head>
+	<body>
+		<h1>Astro</h1>
+	</body>
+</html>
diff --git a/packages/astro/test/fontsource.test.js b/packages/astro/test/fontsource.test.js
new file mode 100644
index 000000000..1c75d0125
--- /dev/null
+++ b/packages/astro/test/fontsource.test.js
@@ -0,0 +1,20 @@
+import { expect } from 'chai';
+import * as cheerio from 'cheerio';
+import { loadFixture } from './test-utils.js';
+
+describe('@fontsource/* packages', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({ root: './fixtures/fontsource-package/' });
+		await fixture.build();
+	});
+
+	it('can be imported in frontmatter', async () => {
+		const html = await fixture.readFile('/index.html');
+		const $ = cheerio.load(html);
+		const assetPath = $('link').attr('href');
+		const css = await fixture.readFile(assetPath);
+		expect(css).to.contain('Montserrat');
+	});
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index e847f793f..e3ed897d2 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -542,7 +542,7 @@ importers:
       strip-ansi: ^7.0.1
       supports-esm: ^1.0.0
       tsconfig-resolver: ^3.0.1
-      vite: ^2.9.9
+      vite: ^2.9.10
       yargs-parser: ^21.0.1
       zod: ^3.17.3
     dependencies:
@@ -599,7 +599,7 @@ importers:
       strip-ansi: 7.0.1
       supports-esm: 1.0.0
       tsconfig-resolver: 3.0.1
-      vite: 2.9.9_sass@1.52.2
+      vite: 2.9.10_sass@1.52.2
       yargs-parser: 21.0.1
       zod: 3.17.3
     devDependencies:
@@ -1367,6 +1367,14 @@ importers:
       '@astrojs/vue': link:../../../../integrations/vue
       astro: link:../../..
 
+  packages/astro/test/fixtures/fontsource-package:
+    specifiers:
+      '@fontsource/montserrat': 4.5.11
+      astro: workspace:*
+    dependencies:
+      '@fontsource/montserrat': 4.5.11
+      astro: link:../../..
+
   packages/astro/test/fixtures/legacy-build:
     specifiers:
       '@astrojs/vue': workspace:*
@@ -3895,6 +3903,10 @@ packages:
       - supports-color
     dev: true
 
+  /@fontsource/montserrat/4.5.11:
+    resolution: {integrity: sha512-XAYZmprnZDVSLIeEiB3evVG2JD+yoR9aT+I6LCOcwZFQ6ro9UPpopDncqoqwv+j5M0/UjyAP6ov70+L/fmP8Gg==}
+    dev: false
+
   /@formatjs/ecma402-abstract/1.11.4:
     resolution: {integrity: sha512-EBikYFp2JCdIfGEb5G9dyCkTGDmC57KSHhRQOC3aYxoPWVZvfWCDjZwkGYHN7Lis/fmuWl906bnNTJifDQ3sXw==}
     dependencies:
@@ -13592,6 +13604,31 @@ packages:
       - supports-color
     dev: true
 
+  /vite/2.9.10_sass@1.52.2:
+    resolution: {integrity: sha512-TwZRuSMYjpTurLqXspct+HZE7ONiW9d+wSWgvADGxhDPPyoIcNywY+RX4ng+QpK30DCa1l/oZgi2PLZDibhzbQ==}
+    engines: {node: '>=12.2.0'}
+    hasBin: true
+    peerDependencies:
+      less: '*'
+      sass: '*'
+      stylus: '*'
+    peerDependenciesMeta:
+      less:
+        optional: true
+      sass:
+        optional: true
+      stylus:
+        optional: true
+    dependencies:
+      esbuild: 0.14.42
+      postcss: 8.4.14
+      resolve: 1.22.0
+      rollup: 2.75.5
+      sass: 1.52.2
+    optionalDependencies:
+      fsevents: 2.3.2
+    dev: false
+
   /vite/2.9.9:
     resolution: {integrity: sha512-ffaam+NgHfbEmfw/Vuh6BHKKlI/XIAhxE5QSS7gFLIngxg171mg1P3a4LSRME0z2ZU1ScxoKzphkipcYwSD5Ew==}
     engines: {node: '>=12.2.0'}
@@ -13616,31 +13653,6 @@ packages:
       fsevents: 2.3.2
     dev: false
 
-  /vite/2.9.9_sass@1.52.2:
-    resolution: {integrity: sha512-ffaam+NgHfbEmfw/Vuh6BHKKlI/XIAhxE5QSS7gFLIngxg171mg1P3a4LSRME0z2ZU1ScxoKzphkipcYwSD5Ew==}
-    engines: {node: '>=12.2.0'}
-    hasBin: true
-    peerDependencies:
-      less: '*'
-      sass: '*'
-      stylus: '*'
-    peerDependenciesMeta:
-      less:
-        optional: true
-      sass:
-        optional: true
-      stylus:
-        optional: true
-    dependencies:
-      esbuild: 0.14.42
-      postcss: 8.4.14
-      resolve: 1.22.0
-      rollup: 2.75.5
-      sass: 1.52.2
-    optionalDependencies:
-      fsevents: 2.3.2
-    dev: false
-
   /vm2/3.9.9:
     resolution: {integrity: sha512-xwTm7NLh/uOjARRBs8/95H0e8fT3Ukw5D/JJWhxMbhKzNh1Nu981jQKvkep9iKYNxzlVrdzD0mlBGkDKZWprlw==}
     engines: {node: '>=6.0'}