diff --git a/composer-dist.json b/composer-dist.json
index a5b830e5e..8166b952d 100644
--- a/composer-dist.json
+++ b/composer-dist.json
@@ -9,6 +9,7 @@
         "sabre/dav": "^4.",
         "sabre/xml": "*",
         "slim/slim": "^4.0",
+        "guzzlehttp/psr7": "*",
         "erusev/parsedown": "*",
         "erusev/parsedown-extra": "*",
         "pear/log": "*",