diff --git a/isthmus/src/main/java/io/substrait/isthmus/FeatureBoard.java b/isthmus/src/main/java/io/substrait/isthmus/FeatureBoard.java
index 9c5985b8..8c332e74 100644
--- a/isthmus/src/main/java/io/substrait/isthmus/FeatureBoard.java
+++ b/isthmus/src/main/java/io/substrait/isthmus/FeatureBoard.java
@@ -1,6 +1,7 @@
 package io.substrait.isthmus;
 
 import io.substrait.isthmus.SubstraitRelVisitor.CrossJoinPolicy;
+import org.apache.calcite.sql.validate.SqlConformance;
 import org.apache.calcite.sql.validate.SqlConformanceEnum;
 import org.immutables.value.Value;
 
@@ -27,7 +28,7 @@ public boolean allowsSqlBatch() {
    * @return the selected built-in Calcite SQL compatibility mode.
    */
   @Value.Default
-  public SqlConformanceEnum sqlConformanceMode() {
+  public SqlConformance sqlConformanceMode() {
     return SqlConformanceEnum.DEFAULT;
   }
 
diff --git a/isthmus/src/test/java/io/substrait/isthmus/PlanEntryPointTest.java b/isthmus/src/test/java/io/substrait/isthmus/PlanEntryPointTest.java
index b7f602c5..3b23d82d 100644
--- a/isthmus/src/test/java/io/substrait/isthmus/PlanEntryPointTest.java
+++ b/isthmus/src/test/java/io/substrait/isthmus/PlanEntryPointTest.java
@@ -6,6 +6,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import io.substrait.isthmus.SubstraitRelVisitor.CrossJoinPolicy;
+import org.apache.calcite.sql.validate.SqlConformance;
 import org.apache.calcite.sql.validate.SqlConformanceEnum;
 import org.junit.jupiter.api.Test;
 import picocli.CommandLine;
@@ -36,7 +37,8 @@ void customFeatureBoard() {
             "SELECT * FROM foo");
     FeatureBoard features = planEntryPoint.buildFeatureBoard();
     assertTrue(features.allowsSqlBatch());
-    assertEquals(SqlConformanceEnum.SQL_SERVER_2008, features.sqlConformanceMode());
+    assertEquals(
+        (SqlConformance) SqlConformanceEnum.SQL_SERVER_2008, features.sqlConformanceMode());
     assertEquals(CrossJoinPolicy.CONVERT_TO_INNER_JOIN, features.crossJoinPolicy());
   }