diff --git a/runtime/CSharp/src/Atn/LexerATNSimulator.cs b/runtime/CSharp/src/Atn/LexerATNSimulator.cs
index 3c9479ca80..4644decd4f 100644
--- a/runtime/CSharp/src/Atn/LexerATNSimulator.cs
+++ b/runtime/CSharp/src/Atn/LexerATNSimulator.cs
@@ -779,7 +779,7 @@ public int Column
 		}
 
 
-		public void Consume(ICharStream input)
+		public virtual void Consume(ICharStream input)
 		{
 			int curChar = input.LA(1);
 			if (curChar == '\n')