diff --git a/core/src/main/kotlin/com/github/avrokotlin/avro4k/Avro.kt b/core/src/main/kotlin/com/github/avrokotlin/avro4k/Avro.kt
index 1485f271..0a63ae47 100644
--- a/core/src/main/kotlin/com/github/avrokotlin/avro4k/Avro.kt
+++ b/core/src/main/kotlin/com/github/avrokotlin/avro4k/Avro.kt
@@ -42,7 +42,7 @@ public sealed class Avro(
     private val schemaCache: Cache<SerialDescriptor, Schema> = WeakKeyCache()
 
     internal val recordResolver = RecordResolver(this)
-    internal val polymorphicResolver = PolymorphicResolver(serializersModule)
+    internal val polymorphicResolver = PolymorphicResolver(serializersModule) { schema(it).fullName }
     internal val enumResolver = EnumResolver()
 
     public companion object Default : Avro(
diff --git a/core/src/main/kotlin/com/github/avrokotlin/avro4k/internal/PolymorphicResolver.kt b/core/src/main/kotlin/com/github/avrokotlin/avro4k/internal/PolymorphicResolver.kt
index 462fa2db..d4c12ee3 100644
--- a/core/src/main/kotlin/com/github/avrokotlin/avro4k/internal/PolymorphicResolver.kt
+++ b/core/src/main/kotlin/com/github/avrokotlin/avro4k/internal/PolymorphicResolver.kt
@@ -4,7 +4,10 @@ import com.github.avrokotlin.avro4k.AvroAlias
 import kotlinx.serialization.descriptors.SerialDescriptor
 import kotlinx.serialization.modules.SerializersModule
 
-internal class PolymorphicResolver(private val serializersModule: SerializersModule) {
+internal class PolymorphicResolver(
+    private val serializersModule: SerializersModule,
+    private val schemaNameResolver: (SerialDescriptor) -> String,
+) {
     private val cache = WeakKeyCache<SerialDescriptor, Map<String, String>>()
 
     fun getFullNamesAndAliasesToSerialName(descriptor: SerialDescriptor): Map<String, String> {
@@ -12,7 +15,7 @@ internal class PolymorphicResolver(private val serializersModule: SerializersMod
             descriptor.possibleSerializationSubclasses(serializersModule)
                 .flatMap {
                     sequence {
-                        yield(it.nonNullSerialName to it.nonNullSerialName)
+                        yield(schemaNameResolver(it) to it.nonNullSerialName)
                         it.findAnnotation<AvroAlias>()?.value?.forEach { alias ->
                             yield(alias to it.nonNullSerialName)
                         }
diff --git a/core/src/test/kotlin/com/github/avrokotlin/avro4k/encoding/SealedClassEncodingTest.kt b/core/src/test/kotlin/com/github/avrokotlin/avro4k/encoding/SealedClassEncodingTest.kt
index 83c20bb2..6f6196f9 100644
--- a/core/src/test/kotlin/com/github/avrokotlin/avro4k/encoding/SealedClassEncodingTest.kt
+++ b/core/src/test/kotlin/com/github/avrokotlin/avro4k/encoding/SealedClassEncodingTest.kt
@@ -7,6 +7,7 @@ import com.github.avrokotlin.avro4k.recordWithSchema
 import com.github.avrokotlin.avro4k.schema
 import io.kotest.core.spec.style.StringSpec
 import kotlinx.serialization.Serializable
+import org.apache.avro.generic.GenericData
 
 internal class SealedClassEncodingTest : StringSpec({
     "encode/decode sealed classes" {
@@ -15,6 +16,13 @@ internal class SealedClassEncodingTest : StringSpec({
         AvroAssertions.assertThat<Operation>(Operation.Binary.Add(1, 2))
             .isEncodedAs(recordWithSchema(Avro.schema<Operation.Binary.Add>(), 1, 2))
     }
+    "encode/decode sealed class union with value class primitive, enum and record subtypes" {
+        val shapeSchema = Avro.schema<Shape>()
+        val colorSchema = shapeSchema.types.first { it.name == "Color" }
+        AvroAssertions.assertThat<Shape>(Shape.Label("hello")).isEncodedAs("hello")
+        AvroAssertions.assertThat<Shape>(Shape.Color.RED).isEncodedAs(GenericData.get().createEnum("RED", colorSchema))
+        AvroAssertions.assertThat<Shape>(Shape.Circle(5)).isEncodedAs(recordWithSchema(Avro.schema<Shape.Circle>(), 5))
+    }
     "encode/decode nullable sealed classes" {
         AvroAssertions.assertThat(ReferencingNullableSealedClass(Operation.Binary.Add(1, 2)))
             .isEncodedAs(record(recordWithSchema(Avro.schema<Operation.Binary.Add>(), 1, 2)))
@@ -27,6 +35,19 @@ internal class SealedClassEncodingTest : StringSpec({
             .isEncodedAs(null)
     }
 }) {
+    @Serializable
+    private sealed interface Shape {
+        @JvmInline
+        @Serializable
+        value class Label(val value: String) : Shape
+
+        @Serializable
+        enum class Color : Shape { RED, BLUE }
+
+        @Serializable
+        data class Circle(val radius: Int) : Shape
+    }
+
     @Serializable
     private data class ReferencingSealedClass(
         val notNullable: Operation,
diff --git a/kotlin-generator/src/main/kotlin/com/github/avrokotlin/avro4k/KotlinGenerator.kt b/kotlin-generator/src/main/kotlin/com/github/avrokotlin/avro4k/KotlinGenerator.kt
index 71f2e660..700f86de 100644
--- a/kotlin-generator/src/main/kotlin/com/github/avrokotlin/avro4k/KotlinGenerator.kt
+++ b/kotlin-generator/src/main/kotlin/com/github/avrokotlin/avro4k/KotlinGenerator.kt
@@ -332,6 +332,7 @@ public class KotlinGenerator(
      * ```kotlin
      * @Serializable
      * sealed interface <potentialAnonymousBaseName>Union {
+     *     @AvroAlias("<Type full name>")
      *     @JvmInline
      *     @Serializable
      *     value class For<Type name>(val value: <Type full name>) : <potentialAnonymousBaseName>Union
diff --git a/kotlin-generator/src/test/expected-sources/complex-union-in-record/ComplexUnionInRecord.kt b/kotlin-generator/src/test/expected-sources/complex-union-in-record/ComplexUnionInRecord.kt
index 4491e5d6..9c591654 100644
--- a/kotlin-generator/src/test/expected-sources/complex-union-in-record/ComplexUnionInRecord.kt
+++ b/kotlin-generator/src/test/expected-sources/complex-union-in-record/ComplexUnionInRecord.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.AvroDefault
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
@@ -25,18 +26,21 @@ public data class ComplexUnionInRecord(
     @Serializable
     @AvroGenerated("""["null",{"type":"record","name":"NestedRecord","fields":[{"name":"id","type":"string"},{"name":"value","type":"int"}]},{"type":"enum","name":"Status","symbols":["ACTIVE","INACTIVE","PENDING"]},{"type":"array","items":"string"}]""")
     public sealed interface TheFieldUnion {
+        @AvroAlias("NestedRecord")
         @JvmInline
         @Serializable
         public value class ForNestedRecord(
             public val `value`: NestedRecord,
         ) : TheFieldUnion
 
+        @AvroAlias("Status")
         @JvmInline
         @Serializable
         public value class ForStatus(
             public val `value`: Status,
         ) : TheFieldUnion
 
+        @AvroAlias("array")
         @JvmInline
         @Serializable
         public value class ForArray(
diff --git a/kotlin-generator/src/test/expected-sources/field-naming-camel-case/ns/CamelCaseRecord.kt b/kotlin-generator/src/test/expected-sources/field-naming-camel-case/ns/CamelCaseRecord.kt
index 2d77a8a3..7ce24da6 100644
--- a/kotlin-generator/src/test/expected-sources/field-naming-camel-case/ns/CamelCaseRecord.kt
+++ b/kotlin-generator/src/test/expected-sources/field-naming-camel-case/ns/CamelCaseRecord.kt
@@ -48,12 +48,14 @@ public data class CamelCaseRecord(
     @Serializable
     @AvroGenerated("""["string",{"type":"enum","name":"StatusFlag","namespace":"ns","symbols":["ACTIVE","INACTIVE"]},"null"]""")
     public sealed interface AccountStatusUnion {
+        @AvroAlias("string")
         @JvmInline
         @Serializable
         public value class ForString(
             public val `value`: String,
         ) : AccountStatusUnion
 
+        @AvroAlias("ns.StatusFlag")
         @JvmInline
         @Serializable
         public value class ForStatusFlag(
diff --git a/kotlin-generator/src/test/expected-sources/root-complex-union/TestSchema.kt b/kotlin-generator/src/test/expected-sources/root-complex-union/TestSchema.kt
index 259f7bbc..51ad0bd6 100644
--- a/kotlin-generator/src/test/expected-sources/root-complex-union/TestSchema.kt
+++ b/kotlin-generator/src/test/expected-sources/root-complex-union/TestSchema.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.AvroFixed
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
@@ -20,30 +21,35 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["null","string","int",{"type":"record","name":"NestedRecord","fields":[{"name":"field","type":"string","doc":"field doc"}]},{"type":"enum","name":"AnEnum","symbols":["A","B","C"]},{"type":"fixed","name":"AFixed","size":5},{"type":"array","items":"int"},{"type":"map","values":["null","double"]}]""")
 public sealed interface TestSchema {
+    @AvroAlias("string")
     @JvmInline
     @Serializable
     public value class ForString(
         public val `value`: String,
     ) : TestSchema
 
+    @AvroAlias("int")
     @JvmInline
     @Serializable
     public value class ForInt(
         public val `value`: Int,
     ) : TestSchema
 
+    @AvroAlias("NestedRecord")
     @JvmInline
     @Serializable
     public value class ForNestedRecord(
         public val `value`: NestedRecord,
     ) : TestSchema
 
+    @AvroAlias("AnEnum")
     @JvmInline
     @Serializable
     public value class ForAnEnum(
         public val `value`: AnEnum,
     ) : TestSchema
 
+    @AvroAlias("AFixed")
     @JvmInline
     @Serializable
     public value class ForAFixed(
@@ -51,12 +57,14 @@ public sealed interface TestSchema {
         public val `value`: ByteArray,
     ) : TestSchema
 
+    @AvroAlias("array")
     @JvmInline
     @Serializable
     public value class ForArray(
         public val `value`: List<Int>,
     ) : TestSchema
 
+    @AvroAlias("map")
     @JvmInline
     @Serializable
     public value class ForMap(
diff --git a/kotlin-generator/src/test/expected-sources/root-map/TestSchemaMapUnion.kt b/kotlin-generator/src/test/expected-sources/root-map/TestSchemaMapUnion.kt
index c7858df8..9752e7b7 100644
--- a/kotlin-generator/src/test/expected-sources/root-map/TestSchemaMapUnion.kt
+++ b/kotlin-generator/src/test/expected-sources/root-map/TestSchemaMapUnion.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
 import com.github.avrokotlin.avro4k.`internal`.AvroGenerated
@@ -15,12 +16,14 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["double","null","int"]""")
 public sealed interface TestSchemaMapUnion {
+    @AvroAlias("double")
     @JvmInline
     @Serializable
     public value class ForDouble(
         public val `value`: Double,
     ) : TestSchemaMapUnion
 
+    @AvroAlias("int")
     @JvmInline
     @Serializable
     public value class ForInt(
diff --git a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchema.kt b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchema.kt
index 052dabf3..bc587921 100644
--- a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchema.kt
+++ b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchema.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
 import com.github.avrokotlin.avro4k.`internal`.AvroGenerated
@@ -17,18 +18,21 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["int","null",{"type":"map","values":["string","null",{"type":"array","items":["long","null",{"type":"map","values":["boolean","null"]}]}]},{"type":"array","items":["long","null","double"]}]""")
 public sealed interface TestSchema {
+    @AvroAlias("int")
     @JvmInline
     @Serializable
     public value class ForInt(
         public val `value`: Int,
     ) : TestSchema
 
+    @AvroAlias("map")
     @JvmInline
     @Serializable
     public value class ForMap(
         public val `value`: Map<String, TestSchemaMapUnion?>,
     ) : TestSchema
 
+    @AvroAlias("array")
     @JvmInline
     @Serializable
     public value class ForArray(
diff --git a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaArrayUnion.kt b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaArrayUnion.kt
index f9409735..c68a4198 100644
--- a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaArrayUnion.kt
+++ b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaArrayUnion.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
 import com.github.avrokotlin.avro4k.`internal`.AvroGenerated
@@ -15,12 +16,14 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["long","null","double"]""")
 public sealed interface TestSchemaArrayUnion {
+    @AvroAlias("long")
     @JvmInline
     @Serializable
     public value class ForLong(
         public val `value`: Long,
     ) : TestSchemaArrayUnion
 
+    @AvroAlias("double")
     @JvmInline
     @Serializable
     public value class ForDouble(
diff --git a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapArrayUnion.kt b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapArrayUnion.kt
index 57773607..86504c2f 100644
--- a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapArrayUnion.kt
+++ b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapArrayUnion.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
 import com.github.avrokotlin.avro4k.`internal`.AvroGenerated
@@ -17,12 +18,14 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["long","null",{"type":"map","values":["boolean","null"]}]""")
 public sealed interface TestSchemaMapArrayUnion {
+    @AvroAlias("long")
     @JvmInline
     @Serializable
     public value class ForLong(
         public val `value`: Long,
     ) : TestSchemaMapArrayUnion
 
+    @AvroAlias("map")
     @JvmInline
     @Serializable
     public value class ForMap(
diff --git a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapUnion.kt b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapUnion.kt
index 50f01be4..1fee3616 100644
--- a/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapUnion.kt
+++ b/kotlin-generator/src/test/expected-sources/root-union-with-nested-map-and-array-unions/TestSchemaMapUnion.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
 import com.github.avrokotlin.avro4k.`internal`.AvroGenerated
@@ -15,12 +16,14 @@ import kotlinx.serialization.Serializable
 @Serializable
 @AvroGenerated("""["string","null",{"type":"array","items":["long","null",{"type":"map","values":["boolean","null"]}]}]""")
 public sealed interface TestSchemaMapUnion {
+    @AvroAlias("string")
     @JvmInline
     @Serializable
     public value class ForString(
         public val `value`: String,
     ) : TestSchemaMapUnion
 
+    @AvroAlias("array")
     @JvmInline
     @Serializable
     public value class ForArray(
diff --git a/kotlin-generator/src/test/expected-sources/types-across-multiple-files/Union.kt b/kotlin-generator/src/test/expected-sources/types-across-multiple-files/Union.kt
index de1eeb35..0a5affbb 100644
--- a/kotlin-generator/src/test/expected-sources/types-across-multiple-files/Union.kt
+++ b/kotlin-generator/src/test/expected-sources/types-across-multiple-files/Union.kt
@@ -3,6 +3,7 @@
     ExperimentalAvro4kApi::class,
 )
 
+import com.github.avrokotlin.avro4k.AvroAlias
 import com.github.avrokotlin.avro4k.AvroFixed
 import com.github.avrokotlin.avro4k.ExperimentalAvro4kApi
 import com.github.avrokotlin.avro4k.InternalAvro4kApi
@@ -18,24 +19,28 @@ import ns2.Enum
 @Serializable
 @AvroGenerated("""[{"type":"record","name":"Record","namespace":"ns","fields":[{"name":"field","type":"int"}]},{"type":"record","name":"RecordWithoutNamespace","fields":[{"name":"field","type":"int"}]},{"type":"enum","name":"Enum","namespace":"ns2","symbols":["FIRST","SECOND"]},{"type":"fixed","name":"FixedType","size":12},"string","bytes"]""")
 public sealed interface Union {
+    @AvroAlias("ns.Record")
     @JvmInline
     @Serializable
     public value class ForRecord(
         public val `value`: Record,
     ) : Union
 
+    @AvroAlias("RecordWithoutNamespace")
     @JvmInline
     @Serializable
     public value class ForRecordWithoutNamespace(
         public val `value`: RecordWithoutNamespace,
     ) : Union
 
+    @AvroAlias("ns2.Enum")
     @JvmInline
     @Serializable
     public value class ForEnum(
         public val `value`: Enum,
     ) : Union
 
+    @AvroAlias("FixedType")
     @JvmInline
     @Serializable
     public value class ForFixedType(
@@ -43,12 +48,14 @@ public sealed interface Union {
         public val `value`: ByteArray,
     ) : Union
 
+    @AvroAlias("string")
     @JvmInline
     @Serializable
     public value class ForString(
         public val `value`: String,
     ) : Union
 
+    @AvroAlias("bytes")
     @JvmInline
     @Serializable
     public value class ForBytes(