diff --git a/examples/cbindings/cbindings_chat_tui.c b/examples/cbindings/cbindings_chat_tui.c
index 5bc3faf..7ae722c 100644
--- a/examples/cbindings/cbindings_chat_tui.c
+++ b/examples/cbindings/cbindings_chat_tui.c
@@ -672,7 +672,7 @@ int main(int argc, char *argv[]) {
     char config[2048];
     if (peer) {
         snprintf(config, sizeof(config),
-                 "{\"name\":\"%s\",\"port\":%d,\"clusterId\":%d,\"shardId\":%d,\"staticPeer\":\"%s\"}",
+                 "{\"name\":\"%s\",\"port\":%d,\"clusterId\":%d,\"shardId\":%d,\"staticPeers\":[\"%s\"]}",
                  name, port, cluster_id, shard_id, peer);
     } else {
         snprintf(config, sizeof(config),
diff --git a/library/api/client_api.nim b/library/api/client_api.nim
index 10c8d76..5a29d12 100644
--- a/library/api/client_api.nim
+++ b/library/api/client_api.nim
@@ -44,6 +44,9 @@ proc createChatClient(
     if config.hasKey("shardId"):
       wakuCfg.shardId = @[config["shardId"].getInt().uint16]
     
+    if config.hasKey("clusterId") or config.hasKey("shardId"):
+      wakuCfg.pubsubTopic = "/waku/2/rs/" & $wakuCfg.clusterId & "/" & $wakuCfg.shardId[0]
+
     if config.hasKey("staticPeers"):
       wakuCfg.staticPeers = @[]
       for peer in config["staticPeers"]: