diff --git a/nip11/fetch.go b/nip11/fetch.go
index 562c425..065913a 100644
--- a/nip11/fetch.go
+++ b/nip11/fetch.go
@@ -41,6 +41,7 @@ func Fetch(ctx context.Context, u string) (info RelayInformationDocument, err er
 
 	// add the NIP-11 header
 	req.Header.Add("Accept", "application/nostr+json")
+	req.Header.Add("User-Agent", "nostrlib/go")
 
 	// send the request
 	resp, err := http.DefaultClient.Do(req)
diff --git a/sdk/specific_event.go b/sdk/specific_event.go
index cad0c94..1742200 100644
--- a/sdk/specific_event.go
+++ b/sdk/specific_event.go
@@ -91,6 +91,8 @@ func (sys *System) FetchSpecificEvent(
 		relays = nostr.AppendUnique(relays, sys.FallbackRelays.Next())
 		fallback = append(fallback, sys.FallbackRelays.Next(), sys.FallbackRelays.Next())
 		priorityRelays = append(priorityRelays, v.Relays...)
+	default:
+		return nil, nil, fmt.Errorf("can't call sys.FetchSpecificEvent() with a %v", pointer)
 	}
 
 	// try to fetch in our internal eventstore first