diff --git a/proto/ignition/msgs/material.proto b/proto/ignition/msgs/material.proto
index 22913884..dd0dceed 100644
--- a/proto/ignition/msgs/material.proto
+++ b/proto/ignition/msgs/material.proto
@@ -117,4 +117,8 @@ message Material
 
   /// \brief Physically Based Rendering (PBR) material properties
   PBR pbr                = 10;
+
+  /// \brief Render order. The higher value will be rendered on top of the
+  /// other coplanar polygons
+  double render_order    = 11;
 }