diff --git a/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/nativefst/automaton/RegExp.java b/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/nativefst/automaton/RegExp.java
index 58fdae349a75..f04187ca4c25 100644
--- a/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/nativefst/automaton/RegExp.java
+++ b/pinot-segment-local/src/main/java/org/apache/pinot/segment/local/utils/nativefst/automaton/RegExp.java
@@ -275,7 +275,7 @@ static RegExp makeInterval(int min, int max, int digits) {
    * Same as <code>toAutomaton(null)</code> (empty automaton map).
    */
   public Automaton toAutomaton() {
-    return toAutomatonAllowMutate(null, null, true);
+    return toAutomatonAllowMutate(null, null, false);
   }
 
   private Automaton toAutomatonAllowMutate(Map<String, Automaton> automata, AutomatonProvider automatonProvider,