diff --git a/ruma-client-api/src/r0/session/login.rs b/ruma-client-api/src/r0/session/login.rs
index 21e3aed4..ccd9c4df 100644
--- a/ruma-client-api/src/r0/session/login.rs
+++ b/ruma-client-api/src/r0/session/login.rs
@@ -54,6 +54,7 @@ ruma_api! {
         /// Client configuration provided by the server.
         ///
         /// If present, clients SHOULD use the provided object to reconfigure themselves.
+        #[serde(skip_serializing_if = "Option::is_none")]
         pub well_known: Option<DiscoveryInfo>,
     }