diff --git a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
index 331e3a447bd..d73f91a6dd1 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
+++ b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
@@ -331,6 +331,8 @@ func (s *GenericAPIServer) InstallAPIGroup(apiGroupInfo *APIGroupInfo) error {
 	return nil
 }
 
+// AddAPIGroupForDiscovery adds the specified group to the list served to discovery queries.
+// Groups are listed in the order they are added.
 func (s *GenericAPIServer) AddAPIGroupForDiscovery(apiGroup metav1.APIGroup) {
 	s.apiGroupsForDiscoveryLock.Lock()
 	defer s.apiGroupsForDiscoveryLock.Unlock()