diff --git a/api/openapi.yaml b/api/openapi.yaml
index c1aed30..b17b539 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -57,6 +57,8 @@ paths:
                   $ref: '#/components/schemas/Title'
         '204':
           description: No titles found
+        '400':
+          description: Request params are not correct
         '500':
           description: Unknown server error
 
@@ -167,6 +169,10 @@ paths:
                 $ref: '#/components/schemas/User'
         '404':
           description: User not found
+        '400':
+          description: Request params are not correct
+        '500':
+          description: Unknown server error
 
     # patch:
     #   summary: Update user