diff --git a/proto/substrait/algebra.proto b/proto/substrait/algebra.proto
index 8279ece67..127cd0a93 100644
--- a/proto/substrait/algebra.proto
+++ b/proto/substrait/algebra.proto
@@ -1633,8 +1633,12 @@ message AggregateFunction {
   }
 }
 
-// This rel is used  to create references,
+// This rel is used to create references,
 // in case we refer to a RelRoot field names will be ignored
 message ReferenceRel {
+  // points to a PlanRel in Plan.relations (ordinal reference)
   int32 subtree_ordinal = 1;
+
+  // points to a subtree_anchor in PlanRel (for non-ordinal reference)
+  uint32 subtree_reference = 2;
 }
diff --git a/proto/substrait/plan.proto b/proto/substrait/plan.proto
index e5657fb8f..768392f55 100644
--- a/proto/substrait/plan.proto
+++ b/proto/substrait/plan.proto
@@ -19,6 +19,9 @@ message PlanRel {
     // The root of a relation tree
     RelRoot root = 2;
   }
+
+  // provides a non-ordinal anchor for ReferenceRel
+  uint32 subtree_anchor = 3;
 }
 
 // Describe a set of operations to complete.