diff --git a/Makefile b/Makefile
index b67dfb44..db7f9d96 100644
--- a/Makefile
+++ b/Makefile
@@ -154,7 +154,7 @@ run:
 
 define DOCKERFILE_APIDOCS_LINT
 FROM $(NODE_IMAGE)
-RUN yarn global add @redocly/openapi-cli@1.0.0-beta.54
+RUN yarn global add @redocly/openapi-cli@1.0.0-beta.82
 endef
 export DOCKERFILE_APIDOCS_LINT
 
@@ -176,7 +176,7 @@ export DOCKERFILE_RELEASE
 
 define DOCKERFILE_APIDOCS_GEN
 FROM $(NODE_IMAGE)
-RUN yarn global add redoc-cli@0.12.2
+RUN yarn global add redoc-cli@0.13.7
 endef
 export DOCKERFILE_APIDOCS_GEN
 
diff --git a/apidocs/openapi.yaml b/apidocs/openapi.yaml
index 70020c1b..fad07684 100644
--- a/apidocs/openapi.yaml
+++ b/apidocs/openapi.yaml
@@ -370,6 +370,8 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/Conf'
+        '400':
+          description: invalid request.
         '500':
           description: internal server error.