diff --git a/core/src/execution/proto/expr.proto b/core/src/execution/proto/expr.proto
index c2a88a7eb..605e08aad 100644
--- a/core/src/execution/proto/expr.proto
+++ b/core/src/execution/proto/expr.proto
@@ -233,16 +233,20 @@ message Remainder {
   DataType return_type = 4;
 }
 
+enum EvalMode {
+  LEGACY = 0;
+  TRY = 1;
+  ANSI = 2;
+}
+
 message Cast {
   Expr child = 1;
   DataType datatype = 2;
   string timezone = 3;
-  // LEGACY, ANSI, or TRY
-  enum EvalMode {
-  LEGACY = 0;
-  TRY = 1;
-  ANSI = 2;
-  }
+  // Depreciateid: LEGACY, ANSI, or TRY - preserved for backward compatibity
+  string eval_mode_string= 4; // for backward compatibility 
+  EvalMode eval_mode = 5; // New enum field
+  
 }
 
 message Equal {
diff --git a/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala b/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala
index 6eda0547f..170504c55 100644
--- a/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala
+++ b/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala
@@ -525,6 +525,18 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde {
    * @return
    *   The protobuf representation of the expression, or None if the expression is not supported
    */
+
+  def stringToEvalMode(evalModeStr: String): ExprOuterClass.EvalMode =
+    evalModeStr.toUpperCase match {
+      case "LEGACY" => ExprOuterClass.EvalMode.LEGACY
+      case "TRY" => ExprOuterClass.EvalMode.TRY
+      case "ANSI" => ExprOuterClass.EvalMode.ANSI
+      case _ =>
+        throw new IllegalArgumentException(
+          "Invalid eval mode"
+        ) // Assuming we want to catch errors strictly
+    }
+
   def exprToProto(
       expr: Expression,
       input: Seq[Attribute],
@@ -535,12 +547,14 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde {
         childExpr: Option[Expr],
         evalMode: String): Option[Expr] = {
       val dataType = serializeDataType(dt)
+      val evalModeEnum = stringToEvalMode(evalMode) // Convert string to enum
 
       if (childExpr.isDefined && dataType.isDefined) {
         val castBuilder = ExprOuterClass.Cast.newBuilder()
         castBuilder.setChild(childExpr.get)
         castBuilder.setDatatype(dataType.get)
-        castBuilder.setEvalMode(evalMode)
+        // castBuilder.setEvalMode(evalMode)
+        castBuilder.setEvalMode(evalModeEnum) // Set the enum in protobuf
 
         val timeZone = timeZoneId.getOrElse("UTC")
         castBuilder.setTimezone(timeZone)
@@ -1207,7 +1221,7 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde {
                     .newBuilder()
                     .setChild(e)
                     .setDatatype(serializeDataType(IntegerType).get)
-                    .setEvalMode("LEGACY") // year is not affected by ANSI mode
+                    .setEvalMode(stringToEvalMode("LEGACY")) // year is not affected by ANSI mode
                     .build())
                 .build()
             })