diff --git a/src/AwsS3V3/AwsS3V3Adapter.php b/src/AwsS3V3/AwsS3V3Adapter.php
index e45c35c4f..facf4cb28 100644
--- a/src/AwsS3V3/AwsS3V3Adapter.php
+++ b/src/AwsS3V3/AwsS3V3Adapter.php
@@ -173,7 +173,7 @@ private function upload(string $path, $body, Config $config): void
         $key = $this->prefixer->prefixPath($path);
         $options = $this->createOptionsFromConfig($config);
         $acl = $options['params']['ACL'] ?? $this->determineAcl($config);
-        $shouldDetermineMimetype = $body !== '' && ! array_key_exists('ContentType', $options['params']);
+        $shouldDetermineMimetype = ! array_key_exists('ContentType', $options['params']);
 
         if ($shouldDetermineMimetype && $mimeType = $this->mimeTypeDetector->detectMimeType($key, $body)) {
             $options['params']['ContentType'] = $mimeType;