diff --git a/runtime/Java/src/org/antlr/v4/runtime/Parser.java b/runtime/Java/src/org/antlr/v4/runtime/Parser.java
index 761a88b7a..95dee65ee 100644
--- a/runtime/Java/src/org/antlr/v4/runtime/Parser.java
+++ b/runtime/Java/src/org/antlr/v4/runtime/Parser.java
@@ -212,6 +212,7 @@ public abstract class Parser extends Recognizer<Token, ParserATNSimulator<Token>
         return _parseListeners;
     }
 
+	// TODO: make comment directing people to ParseTreeListener
     public void addParseListener(ParseListener<Token> listener) {
 		if ( listener==null ) return;
 		if ( _parseListeners==null ) {