diff --git a/core/commands/pubsub.go b/core/commands/pubsub.go
index ac3234c7879..374757f24f2 100644
--- a/core/commands/pubsub.go
+++ b/core/commands/pubsub.go
@@ -84,6 +84,9 @@ This command outputs data in the following encodings:
 		discover, _ := req.Options["discover"].(bool)
 
 		sub, err := api.PubSub().Subscribe(req.Context, topic, options.PubSub.Discover(discover))
+		if err != nil {
+			return err
+		}
 		defer sub.Close()
 
 		if f, ok := res.(http.Flusher); ok {
diff --git a/core/coreapi/interface/pubsub.go b/core/coreapi/interface/pubsub.go
index 4c9a1d73e5b..d7a21e02f1a 100644
--- a/core/coreapi/interface/pubsub.go
+++ b/core/coreapi/interface/pubsub.go
@@ -38,7 +38,6 @@ type PubSubAPI interface {
 	Ls(context.Context) ([]string, error)
 
 	// Peers list peers we are currently pubsubbing with
-	// TODO: WithTopic
 	Peers(context.Context, ...options.PubSubPeersOption) ([]peer.ID, error)
 
 	// Publish a message to a given pubsub topic