diff --git a/core/src/main/scala/com/avsystem/commons/opaque/BaseOpaque.scala b/core/src/main/scala/com/avsystem/commons/opaque/BaseOpaque.scala
index e3fda6fe7..dfc465f30 100644
--- a/core/src/main/scala/com/avsystem/commons/opaque/BaseOpaque.scala
+++ b/core/src/main/scala/com/avsystem/commons/opaque/BaseOpaque.scala
@@ -2,12 +2,15 @@ package com.avsystem.commons
 package opaque
 
 import com.avsystem.commons.opaque.Castable.<:>
+import com.avsystem.commons.serialization.GenCodec
 
 private[opaque] trait BaseOpaque[From] extends Castable.Ops {
   trait Tag
   type Type
 
-  implicit protected final val castable: From <:> Type = new Castable[From, Type]
-
   def apply(value: From): Type
+
+
+  implicit protected final val castable: From <:> Type = new Castable[From, Type]
+  implicit final def codec(implicit fromCodec: GenCodec[From]): GenCodec[Type] = wrapF(fromCodec)
 }
diff --git a/core/src/main/scala/com/avsystem/commons/opaque/Castable.scala b/core/src/main/scala/com/avsystem/commons/opaque/Castable.scala
index 43bb97fa2..919dccd2e 100644
--- a/core/src/main/scala/com/avsystem/commons/opaque/Castable.scala
+++ b/core/src/main/scala/com/avsystem/commons/opaque/Castable.scala
@@ -1,9 +1,7 @@
 package com.avsystem.commons
 package opaque
 
-private[opaque] final class Castable[A, B] {
-  @inline def apply(a: A): B = a.asInstanceOf[B]
-}
+private[opaque] final class Castable[A, B]
 private[opaque] object Castable {
   type <:>[A, B] = Castable[A, B]
   def apply[A, B](implicit ev: A <:> B): Castable[A, B] = ev
diff --git a/core/src/test/scala/com/avsystem/commons/serialization/CodecTestData.scala b/core/src/test/scala/com/avsystem/commons/serialization/CodecTestData.scala
index 7b3c94240..ac34d474a 100644
--- a/core/src/test/scala/com/avsystem/commons/serialization/CodecTestData.scala
+++ b/core/src/test/scala/com/avsystem/commons/serialization/CodecTestData.scala
@@ -4,6 +4,7 @@ package serialization
 import com.avsystem.commons.annotation.AnnotationAggregate
 import com.avsystem.commons.meta.{AutoOptionalParams, MacroInstances}
 import com.avsystem.commons.misc.{AutoNamedEnum, NamedEnumCompanion, TypedKey}
+import com.avsystem.commons.opaque.{Opaque, Subopaque}
 
 import scala.annotation.meta.getter
 
@@ -134,6 +135,9 @@ object CodecTestData {
   @transparent case class StringId(id: String)
   object StringId extends TransparentWrapperCompanion[String, StringId]
 
+  object SomeOpaque extends Opaque.Default[Int]
+  object SomeSubopaque extends Subopaque.Default[Int]
+
   trait HasSomeStr {
     @name("some.str") def str: String
     @generated def someStrLen: Int = str.length
diff --git a/core/src/test/scala/com/avsystem/commons/serialization/GenCodecRoundtripTest.scala b/core/src/test/scala/com/avsystem/commons/serialization/GenCodecRoundtripTest.scala
index 27ba19dac..8dc26c1d6 100644
--- a/core/src/test/scala/com/avsystem/commons/serialization/GenCodecRoundtripTest.scala
+++ b/core/src/test/scala/com/avsystem/commons/serialization/GenCodecRoundtripTest.scala
@@ -72,6 +72,11 @@ abstract class GenCodecRoundtripTest extends AbstractCodecTest {
     testRoundtrip(StringId("lolfuu"), "lolfuu")
   }
 
+  test("opaque and subopaque") {
+    testRoundtrip(SomeOpaque(42))
+    testRoundtrip(SomeSubopaque(42))
+  }
+
   test("case class") {
     testRoundtrip(SomeCaseClass("dafuq", List(1, 2, 3)))
   }