diff --git a/src/File/MimeType.php b/src/File/MimeType.php
index 3c09469a5..68e7dd8e3 100644
--- a/src/File/MimeType.php
+++ b/src/File/MimeType.php
@@ -385,6 +385,7 @@ public function isValid($value, $file = null)
             $this->type = null;
             if (! empty($this->finfo)) {
                 $this->type = finfo_file($this->finfo, $file);
+                finfo_close($this->finfo);
             }
         }