diff --git a/crates/ruma-federation-api/CHANGELOG.md b/crates/ruma-federation-api/CHANGELOG.md
index 338439df..382cdc27 100644
--- a/crates/ruma-federation-api/CHANGELOG.md
+++ b/crates/ruma-federation-api/CHANGELOG.md
@@ -3,6 +3,7 @@
 Improvements:
 
 * Fix JSON body (de)serialization of `discovery::get_remote_server_keys::batch::v2::Request`
+* Fix query parameter deserialization of `discovery::get_remote_server_keys::batch::v2::Request`
 
 # 0.3.0
 
diff --git a/crates/ruma-federation-api/src/discovery/get_remote_server_keys_batch/v2.rs b/crates/ruma-federation-api/src/discovery/get_remote_server_keys_batch/v2.rs
index 5e86cf27..a340b416 100644
--- a/crates/ruma-federation-api/src/discovery/get_remote_server_keys_batch/v2.rs
+++ b/crates/ruma-federation-api/src/discovery/get_remote_server_keys_batch/v2.rs
@@ -25,6 +25,7 @@ ruma_api! {
         ///
         /// If not supplied, the current time as determined by the notary server is used.
         #[ruma_api(query)]
+        #[serde(default = "MilliSecondsSinceUnixEpoch::now")]
         pub minimum_valid_until_ts: MilliSecondsSinceUnixEpoch,
 
         /// The query criteria.