diff --git a/include/frnetlib/Http.h b/include/frnetlib/Http.h
index 1a542a3..b8b1a18 100644
--- a/include/frnetlib/Http.h
+++ b/include/frnetlib/Http.h
@@ -64,6 +64,7 @@ namespace fr
             RequestedRangeNotSatisfiable = 416,
             ExpectationFailed = 417,
             ImATeapot = 418,
+            UnprocessableEntity = 422,
             UpgradeRequired = 426,
             PreconditionRequired = 428,
             TooManyRequests = 429,