diff --git a/src/utilities/fetch-package-readmes.mjs b/src/utilities/fetch-package-readmes.mjs
index 332123304c87..dcca133d1eed 100644
--- a/src/utilities/fetch-package-readmes.mjs
+++ b/src/utilities/fetch-package-readmes.mjs
@@ -49,9 +49,16 @@ async function main() {
 
     for (const repo of repos) {
       const [owner, packageName] = repo.split('/');
-      const url = `https://raw.githubusercontent.com/${repo}/master/README.md`;
+
+      const response = await api.repos.get({
+        owner,
+        repo: packageName,
+      });
+
+      const defaultBranch =  response.data.default_branch;
+      const url = `https://raw.githubusercontent.com/${repo}/${defaultBranch}/README.md`;
       const htmlUrl = `https://github.com/${repo}`;
-      const editUrl = `${htmlUrl}/edit/master/README.md`;
+      const editUrl = `${htmlUrl}/edit/${defaultBranch}/README.md`;
       const fileName = path.resolve(outputDir, `_${packageName}.mdx`);
 
       let title = packageName;