diff --git a/urdf_sensor/include/urdf_sensor/types.h b/urdf_sensor/include/urdf_sensor/types.h
index 13d0b25..60227ba 100644
--- a/urdf_sensor/include/urdf_sensor/types.h
+++ b/urdf_sensor/include/urdf_sensor/types.h
@@ -66,6 +66,9 @@ class Sensor
   /// sensor name must be unique
   std::string name_;
 
+  /// optional group name
+  std::string group_;
+
   /// update rate in Hz
   double update_rate_;
 
@@ -81,6 +84,7 @@ class Sensor
   void clear()
   {
     name_.clear();
+    group_.clear();
     parent_link_.clear();
     origin_.clear();
     sensor_.reset();