diff --git a/symfony/monolog-bundle/3.7/config/packages/monolog.yaml b/symfony/monolog-bundle/3.7/config/packages/monolog.yaml
index 8c9efa91..9db7d8a7 100644
--- a/symfony/monolog-bundle/3.7/config/packages/monolog.yaml
+++ b/symfony/monolog-bundle/3.7/config/packages/monolog.yaml
@@ -59,3 +59,4 @@ when@prod:
                 type: stream
                 channels: [deprecation]
                 path: php://stderr
+                formatter: monolog.formatter.json