diff --git a/API-Sessions.md b/API-Sessions.md
index afb5bce..df0dab4 100644
--- a/API-Sessions.md
+++ b/API-Sessions.md
@@ -21,6 +21,7 @@ The provided token should be 64 byte (512-bit) of cryptographic strong entropy,
 | --- | --- |
 | 201 | Everything okay, session was created |
 | 403 | User credentials are not correct |
+| 422 | One of the required fields is missing |
 
 ```json
 {