diff --git a/tool/src/org/antlr/v4/tool/Rule.java b/tool/src/org/antlr/v4/tool/Rule.java
index 5a094ee70..f6a132eca 100644
--- a/tool/src/org/antlr/v4/tool/Rule.java
+++ b/tool/src/org/antlr/v4/tool/Rule.java
@@ -56,7 +56,6 @@ public class Rule implements AttributeResolver {
             add(new Attribute("start"));
             add(new Attribute("stop"));
             add(new Attribute("tree"));
-            add(new Attribute("st"));
             add(new Attribute("ctx"));
         }};