diff --git a/src/github.com/matrix-org/dendrite/cmd/syncserver-integration-tests/main.go b/src/github.com/matrix-org/dendrite/cmd/syncserver-integration-tests/main.go
index b0e36c425..bb75b1dfc 100644
--- a/src/github.com/matrix-org/dendrite/cmd/syncserver-integration-tests/main.go
+++ b/src/github.com/matrix-org/dendrite/cmd/syncserver-integration-tests/main.go
@@ -54,6 +54,7 @@ var (
 )
 
 const inputTopic = "syncserverInput"
+const clientTopic = "clientapiOutput"
 
 var exe = test.KafkaExecutor{
 	ZookeeperURI:   zookeeperURI,
@@ -134,6 +135,7 @@ func startSyncServer() (*exec.Cmd, chan error) {
 	cfg.Matrix.ServerName = "localhost"
 	cfg.Listen.SyncAPI = config.Address(syncserverAddr)
 	cfg.Kafka.Topics.OutputRoomEvent = config.Topic(inputTopic)
+	cfg.Kafka.Topics.OutputClientData = config.Topic(clientTopic)
 
 	if err := test.WriteConfig(cfg, dir); err != nil {
 		panic(err)
@@ -177,6 +179,10 @@ func prepareKafka() {
 	if err := exe.CreateTopic(inputTopic); err != nil {
 		panic(err)
 	}
+	exe.DeleteTopic(clientTopic)
+	if err := exe.CreateTopic(clientTopic); err != nil {
+		panic(err)
+	}
 }
 
 func testSyncServer(syncServerCmdChan chan error, userID, since, want string) {
diff --git a/src/github.com/matrix-org/dendrite/common/config/config.go b/src/github.com/matrix-org/dendrite/common/config/config.go
index 50f820124..324561f68 100644
--- a/src/github.com/matrix-org/dendrite/common/config/config.go
+++ b/src/github.com/matrix-org/dendrite/common/config/config.go
@@ -300,6 +300,7 @@ func (config *Dendrite) check() error {
 
 	checkNotZero("kafka.addresses", int64(len(config.Kafka.Addresses)))
 	checkNotEmpty("kafka.topics.output_room_event", string(config.Kafka.Topics.OutputRoomEvent))
+	checkNotEmpty("kafka.topics.output_client_data", string(config.Kafka.Topics.OutputClientData))
 	checkNotEmpty("database.account", string(config.Database.Account))
 	checkNotEmpty("database.device", string(config.Database.Device))
 	checkNotEmpty("database.server_key", string(config.Database.ServerKey))