diff --git a/integration/deterministic-build-output-test.ts b/integration/deterministic-build-output-test.ts
index 3c68275b3ff..efb7b4d83d9 100644
--- a/integration/deterministic-build-output-test.ts
+++ b/integration/deterministic-build-output-test.ts
@@ -60,7 +60,7 @@ test("builds deterministically under different paths", async () => {
         },
       }),
 
-      "postcss.config.mjs": js`
+      "postcss.config.js": js`
         export default {
           plugins: {
             "postcss-import": {},
diff --git a/package.json b/package.json
index 8553764b3af..730d247000e 100644
--- a/package.json
+++ b/package.json
@@ -109,6 +109,7 @@
     "lodash": "^4.17.21",
     "mime": "^3.0.0",
     "patch-package": "^6.5.0",
+    "postcss-load-config": "^4.0.1",
     "prettier": "^2.7.1",
     "prompt-confirm": "^2.0.4",
     "react": "^18.2.0",
@@ -118,13 +119,13 @@
     "remark-gfm": "3.0.1",
     "remark-parse": "^10.0.1",
     "remark-stringify": "^10.0.2",
+    "resolve-bin": "^1.0.1",
     "rollup": "^2.36.1",
     "rollup-plugin-copy": "^3.3.0",
     "semver": "^7.3.7",
     "simple-git": "^3.16.0",
     "to-vfile": "7.2.3",
     "typescript": "^5.1.0",
-    "resolve-bin": "^1.0.1",
     "unified": "^10.1.2",
     "unist-util-remove": "^3.1.0",
     "unist-util-visit": "^4.1.1",
diff --git a/yarn.lock b/yarn.lock
index 5cefca57fa4..ddcbb188ac6 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -10672,7 +10672,7 @@ postcss-load-config@^3.1.0, postcss-load-config@^3.1.4:
 
 postcss-load-config@^4.0.1:
   version "4.0.1"
-  resolved "https://registry.npmjs.org/postcss-load-config/-/postcss-load-config-4.0.1.tgz"
+  resolved "https://registry.npmjs.org/postcss-load-config/-/postcss-load-config-4.0.1.tgz#152383f481c2758274404e4962743191d73875bd"
   integrity sha512-vEJIc8RdiBRu3oRAI0ymerOn+7rPuMvRXslTvZUKZonDHFIczxztIyJ1urxM1x9JXEikvpWWTUUqal5j/8QgvA==
   dependencies:
     lilconfig "^2.0.5"
@@ -10976,11 +10976,16 @@ pumpify@^1.3.3:
     inherits "^2.0.3"
     pump "^2.0.0"
 
-punycode@^2.1.0, punycode@^2.1.1, punycode@^2.3.0:
+punycode@^2.1.0, punycode@^2.1.1:
   version "2.3.0"
   resolved "https://registry.npmjs.org/punycode/-/punycode-2.3.0.tgz#f67fa67c94da8f4d0cfff981aee4118064199b8f"
   integrity sha512-rRV+zQD8tVFys26lAGR9WUuS4iUAngJScM+ZRSKtvl5tKeZ2t5bvdNFdNHBW9FWR4guGHlgmsZ1G7BSm2wTbuA==
 
+punycode@^2.3.0:
+  version "2.3.1"
+  resolved "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz#027422e2faec0b25e1549c3e1bd8309b9133b6e5"
+  integrity sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==
+
 pure-rand@^6.0.0:
   version "6.0.2"
   resolved "https://registry.npmjs.org/pure-rand/-/pure-rand-6.0.2.tgz#a9c2ddcae9b68d736a8163036f088a2781c8b306"