diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 868b2eb..35cc17f 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -417,7 +417,9 @@ function system_requirements($phase) {
         $requirements['file system']['value'] = '';
       }
       if (!empty($description)) {
-        $requirements['file system']['description'] = $description;
+        // We need to wrap it in the #markup property to prevent Twig's
+        // SafeMarkup from double-escaping.
+        $requirements['file system']['description'] = ['#markup' => $description];
         $requirements['file system']['severity'] = REQUIREMENT_ERROR;
       }
     }