diff --git a/doc/api.yaml b/doc/api.yaml
index ebe0866..7e53b07 100644
--- a/doc/api.yaml
+++ b/doc/api.yaml
@@ -1,4 +1,4 @@
-openapi: 3.1.0
+openapi: 3.0.2
 info:
   title: WASAPhoto API
   description: |-