diff --git a/.gitignore b/.gitignore
index c175fb3b488..ca30be32d5b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,5 @@ packages/**/LICENSE.txt
 packages/web-features/data.json
 packages/web-features/data.schema.json
 packages/web-features/types.ts
+data.extended.json
 index.js
diff --git a/scripts/build.ts b/scripts/build.ts
index 3204cd6bd57..af131761952 100644
--- a/scripts/build.ts
+++ b/scripts/build.ts
@@ -80,10 +80,7 @@ function buildExtendedJSON() {
     process.exit(1);
   }
 
-  fs.writeFileSync(
-    new URL("./web-features.extended.json", rootDir),
-    stringify(data),
-  );
+  fs.writeFileSync(new URL("./data.extended.json", rootDir), stringify(data));
 }
 
 function valid(data: any): boolean {