diff --git a/src/drivers/s3.ts b/src/drivers/s3.ts
index 6ef0f5ff..56e358b0 100644
--- a/src/drivers/s3.ts
+++ b/src/drivers/s3.ts
@@ -183,6 +183,7 @@ export default defineDriver((options: S3DriverOptions) => {
 
             opts.headers = {
                 'Content-Type': contentType,
+                'Content-Length': value.length.toString(),
                 ...opts.headers
             }