diff --git a/runtime/Swift/Antlr4/org/antlr/v4/runtime/tree/Trees.swift b/runtime/Swift/Antlr4/org/antlr/v4/runtime/tree/Trees.swift
index 05e4fb559..1773e9a20 100644
--- a/runtime/Swift/Antlr4/org/antlr/v4/runtime/tree/Trees.swift
+++ b/runtime/Swift/Antlr4/org/antlr/v4/runtime/tree/Trees.swift
@@ -121,6 +121,10 @@ public class Trees {
             if let ruleNode = t as? RuleNode {
                 let ruleIndex: Int = ruleNode.getRuleContext().getRuleIndex()
                 let ruleName: String = ruleNames![ruleIndex]
+                let altNumber = (t as! RuleContext).getAltNumber()
+                if altNumber != ATN.INVALID_ALT_NUMBER  {
+                    return "\(ruleName):\(altNumber)"
+                }
                 return ruleName
             } else {
                 if let errorNode = t as? ErrorNode {