diff --git a/capabilities.go b/capabilities.go
index 433b15c..45b7b54 100644
--- a/capabilities.go
+++ b/capabilities.go
@@ -43,6 +43,9 @@ const (
 	// Name of capability to enable the "v3" API for the signaling endpoint.
 	FeatureSignalingV3Api = "signaling-v3"
 
+	// Name of capability that is set if the server supports Federation V2.
+	FeatureFederationV2 = "federation-v2"
+
 	// minCapabilitiesCacheDuration specifies the minimum duration to cache
 	// capabilities.
 	// This could overwrite the "max-age" from a "Cache-Control" header.
diff --git a/hub.go b/hub.go
index d7b1775..05a7d5d 100644
--- a/hub.go
+++ b/hub.go
@@ -1281,6 +1281,10 @@ func (h *Hub) processHelloV2(ctx context.Context, client HandlerClient, message
 		tokenString = message.Hello.Auth.helloV2Params.Token
 		tokenClaims = &HelloV2TokenClaims{}
 	case HelloClientTypeFederation:
+		if !h.backend.capabilities.HasCapabilityFeature(ctx, url, FeatureFederationV2) {
+			return nil, nil, ErrFederationNotSupported
+		}
+
 		tokenString = message.Hello.Auth.federationParams.Token
 		tokenClaims = &FederationTokenClaims{}
 	default:
diff --git a/hub_test.go b/hub_test.go
index 2f75e79..3cf8ea2 100644
--- a/hub_test.go
+++ b/hub_test.go
@@ -699,6 +699,9 @@ func registerBackendHandlerUrl(t *testing.T, router *mux.Router, url string) {
 		if strings.Contains(t.Name(), "V3Api") {
 			features = append(features, "signaling-v3")
 		}
+		if strings.Contains(t.Name(), "Federation") {
+			features = append(features, "federation-v2")
+		}
 		signaling := map[string]interface{}{
 			"foo": "bar",
 			"baz": 42,