https://github.com/geopython/pygeoapi/commit/04b8f3f7889d04fe68e11756dd820f701733dec7

Index: pygeoapi/models/openapi.py
--- pygeoapi/models/openapi.py.orig
+++ pygeoapi/models/openapi.py
@@ -4,7 +4,7 @@
 #
 # Authors: Francesco Bartoli <xbartolone@gmail.com>
 #
-# Copyright (c) 2024 Francesco Bartoli
+# Copyright (c) 2025 Francesco Bartoli
 #
 # Permission is hereby granted, free of charge, to any person
 # obtaining a copy of this software and associated documentation
@@ -40,4 +40,4 @@ class SupportedFormats(Enum):
 
 
 class OAPIFormat(BaseModel):
-    __root__: SupportedFormats = SupportedFormats.YAML
+    root: SupportedFormats = SupportedFormats.YAML
