diff --git a/core/src/execution/datafusion/planner.rs b/core/src/execution/datafusion/planner.rs
index a0b75de3f..20119b13a 100644
--- a/core/src/execution/datafusion/planner.rs
+++ b/core/src/execution/datafusion/planner.rs
@@ -348,16 +348,12 @@ impl PhysicalPlanner {
                 let child = self.create_expr(expr.child.as_ref().unwrap(), input_schema)?;
                 let datatype = to_arrow_datatype(expr.datatype.as_ref().unwrap());
                 let timezone = expr.timezone.clone();
-                let eval_mode = match expr.eval_mode.as_str() {
-                    "ANSI" => EvalMode::Ansi,
-                    "TRY" => EvalMode::Try,
-                    "LEGACY" => EvalMode::Legacy,
-                    other => {
-                        return Err(ExecutionError::GeneralError(format!(
-                            "Invalid Cast EvalMode: \"{other}\""
-                        )))
-                    }
+                let eval_mode = match spark_expression::EvalMode::try_from(expr.eval_mode)? {
+                    spark_expression::EvalMode::Legacy => EvalMode::Legacy,
+                    spark_expression::EvalMode::Try => EvalMode::Try,
+                    spark_expression::EvalMode::Ansi => EvalMode::Ansi,
                 };
+
                 Ok(Arc::new(Cast::new(child, datatype, eval_mode, timezone)))
             }
             ExprStruct::Hour(expr) => {
diff --git a/core/src/execution/proto/expr.proto b/core/src/execution/proto/expr.proto
index be85e8a92..bcd983875 100644
--- a/core/src/execution/proto/expr.proto
+++ b/core/src/execution/proto/expr.proto
@@ -249,12 +249,18 @@ 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
-  string eval_mode = 4;
+  EvalMode eval_mode = 4; 
+  
 }
 
 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 c1188e193..79a75102d 100644
--- a/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala
+++ b/spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala
@@ -19,6 +19,8 @@
 
 package org.apache.comet.serde
 
+import java.util.Locale
+
 import scala.collection.JavaConverters._
 
 import org.apache.spark.internal.Logging
@@ -588,6 +590,18 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde with CometExprShim
    * @return
    *   The protobuf representation of the expression, or None if the expression is not supported
    */
+
+  def stringToEvalMode(evalModeStr: String): ExprOuterClass.EvalMode =
+    evalModeStr.toUpperCase(Locale.ROOT) match {
+      case "LEGACY" => ExprOuterClass.EvalMode.LEGACY
+      case "TRY" => ExprOuterClass.EvalMode.TRY
+      case "ANSI" => ExprOuterClass.EvalMode.ANSI
+      case invalid =>
+        throw new IllegalArgumentException(
+          s"Invalid eval mode '$invalid' "
+        ) // Assuming we want to catch errors strictly
+    }
+
   def exprToProto(
       expr: Expression,
       input: Seq[Attribute],
@@ -598,12 +612,13 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde with CometExprShim
         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(evalModeEnum) // Set the enum in protobuf
 
         val timeZone = timeZoneId.getOrElse("UTC")
         castBuilder.setTimezone(timeZone)
@@ -1305,7 +1320,7 @@ object QueryPlanSerde extends Logging with ShimQueryPlanSerde with CometExprShim
                     .newBuilder()
                     .setChild(e)
                     .setDatatype(serializeDataType(IntegerType).get)
-                    .setEvalMode("LEGACY") // year is not affected by ANSI mode
+                    .setEvalMode(ExprOuterClass.EvalMode.LEGACY)
                     .build())
                 .build()
             })