diff --git a/data4k/src/test/kotlin/dev/forkhandles/lens/DataContainerContract.kt b/data4k/src/test/kotlin/dev/forkhandles/lens/DataContainerContract.kt
index b65bbff..55c267f 100644
--- a/data4k/src/test/kotlin/dev/forkhandles/lens/DataContainerContract.kt
+++ b/data4k/src/test/kotlin/dev/forkhandles/lens/DataContainerContract.kt
@@ -24,6 +24,7 @@ interface MainClassFields<T : SubClassFields> {
     var listSubClassField: List<T>
     var listIntsField: List<Int>
     var listValueField: List<MyType>
+    val listMapped: List<String>
 
     var objectField: T
 
@@ -166,6 +167,7 @@ abstract class DataContainerContract<T : SubClassFields> {
             mapOf(
                 "listField" to listOf("string1", "string2"),
                 "listIntsField" to listOf(1, 2, 3),
+                "listMapped" to listOf(123, 456),
                 "listValueField" to listOf(1, 2, 3),
                 "listSubClassField" to listOf(
                     mapOf("stringField" to "string1"),
@@ -175,6 +177,7 @@ abstract class DataContainerContract<T : SubClassFields> {
             )
         )
         expectThat(input.listField).isEqualTo(listOf("string1", "string2"))
+        expectThat(input.listMapped).isEqualTo(listOf("123", "456"))
         expectThat(input.listIntsField).isEqualTo(listOf(1, 2, 3))
         expectThat(input.listValueField).isEqualTo(listOf(1, 2, 3).map(MyType::of))
         expectThat(input.listSubClassField.map { it.stringField }).isEqualTo(listOf("string1", "string2"))