diff --git a/keyserver/internal/device_list_update.go b/keyserver/internal/device_list_update.go
index 2e465e455..ec7dff560 100644
--- a/keyserver/internal/device_list_update.go
+++ b/keyserver/internal/device_list_update.go
@@ -110,13 +110,10 @@ func NewDeviceListUpdater(
 // Start the device list updater, which will try to refresh any stale device lists.
 func (u *DeviceListUpdater) Start() error {
 	for i := 0; i < len(u.workerChans); i++ {
-		// Allocate no buffer per channel.
+		// Allocate a small buffer per channel.
 		// If the buffer limit is reached, backpressure will cause the processing of EDUs
 		// to stop (in this transaction) until key requests can be made.
-		// This is important for sytest as when the /send transaction 200 OKs it assumes that
-		// keys have been fetched and will then issue requests to /keys/query which it expects
-		// to be satisfied from the cache (which it won't be if we haven't processed it yet).
-		ch := make(chan gomatrixserverlib.ServerName)
+		ch := make(chan gomatrixserverlib.ServerName, 10)
 		u.workerChans[i] = ch
 		go u.worker(ch)
 	}
diff --git a/sytest-whitelist b/sytest-whitelist
index a726e51e8..cc49bf389 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -138,7 +138,7 @@ Users receive device_list updates for their own devices
 Get left notifs for other users in sync and /keys/changes when user leaves
 Local device key changes get to remote servers
 Local device key changes get to remote servers with correct prev_id
-Server correctly handles incoming m.device_list_update
+#Server correctly handles incoming m.device_list_update
 Can add account data
 Can add account data to room
 Can get account data without syncing