diff --git a/datafusion/proto/proto/datafusion.proto b/datafusion/proto/proto/datafusion.proto
index 111c42533cd5..d17bad849365 100644
--- a/datafusion/proto/proto/datafusion.proto
+++ b/datafusion/proto/proto/datafusion.proto
@@ -302,7 +302,7 @@ message LogicalExprNode {
     // Scalar UDF expressions
     ScalarUDFExprNode scalar_udf_expr = 20;
 
-    GetIndexedField getIndexedField = 21;
+    GetIndexedField get_indexed_field = 21;
   }
 }