diff --git a/demoapp/gradle/libs.versions.toml b/demoapp/gradle/libs.versions.toml
index e315ecf6..950a0d45 100644
--- a/demoapp/gradle/libs.versions.toml
+++ b/demoapp/gradle/libs.versions.toml
@@ -11,7 +11,7 @@ voyager = "1.0.0"
 composeImageLoader = "1.7.1"
 napier = "2.7.1"
 buildConfig = "4.1.1"
-kotlinx-coroutines = "1.8.1"
+kotlinx-coroutines = "1.9.0"
 
 [libraries]
 
diff --git a/indispensable/src/commonMain/kotlin/at/asitplus/signum/indispensable/asn1/Asn1Elements.kt b/indispensable/src/commonMain/kotlin/at/asitplus/signum/indispensable/asn1/Asn1Elements.kt
index 5ab83961..aef9c9b6 100644
--- a/indispensable/src/commonMain/kotlin/at/asitplus/signum/indispensable/asn1/Asn1Elements.kt
+++ b/indispensable/src/commonMain/kotlin/at/asitplus/signum/indispensable/asn1/Asn1Elements.kt
@@ -13,6 +13,8 @@ import kotlinx.serialization.descriptors.PrimitiveKind
 import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
 import kotlinx.serialization.encoding.Decoder
 import kotlinx.serialization.encoding.Encoder
+import kotlin.experimental.ExperimentalObjCRefinement
+import kotlin.native.HiddenFromObjC
 
 /**
  * Base ASN.1 data class. Can either be a primitive (holding a value), or a structure (holding other ASN.1 elements)
@@ -231,8 +233,10 @@ sealed class Asn1Element(
     }
 
 
+    @OptIn(ExperimentalObjCRefinement::class)
     @Serializable
     @ConsistentCopyVisibility
+    @HiddenFromObjC
     data class Tag private constructor(
         val tagValue: ULong, val encodedTagLength: Int,
         @Serializable(with = ByteArrayBase64Serializer::class) val encodedTag: ByteArray