diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 86b3cb51..c9575496 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -17,4 +17,4 @@ kotlin-js = { id = "org.jetbrains.kotlin.js", version.ref = "kotlin" }
 kotlin-multiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }
 kotlinter = { id = "org.jmailen.kotlinter", version = "4.1.1" }
 kotlinx-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
-maven-publish = { id = "com.vanniktech.maven.publish", version = "0.26.0" }
+maven-publish = { id = "com.vanniktech.maven.publish", version = "0.27.0" }
diff --git a/koap/api/koap.api b/koap/api/koap.api
index 1bca6a8b..c6865fef 100644
--- a/koap/api/koap.api
+++ b/koap/api/koap.api
@@ -363,10 +363,16 @@ public abstract class com/juul/koap/Message$Option$Observe$Registration {
 
 public final class com/juul/koap/Message$Option$Observe$Registration$Deregister : com/juul/koap/Message$Option$Observe$Registration {
 	public static final field INSTANCE Lcom/juul/koap/Message$Option$Observe$Registration$Deregister;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
 }
 
 public final class com/juul/koap/Message$Option$Observe$Registration$Register : com/juul/koap/Message$Option$Observe$Registration {
 	public static final field INSTANCE Lcom/juul/koap/Message$Option$Observe$Registration$Register;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
 }
 
 public final class com/juul/koap/Message$Option$ProxyScheme : com/juul/koap/Message$Option {
diff --git a/koap/src/commonMain/kotlin/Message.kt b/koap/src/commonMain/kotlin/Message.kt
index 551027b5..41e909fc 100644
--- a/koap/src/commonMain/kotlin/Message.kt
+++ b/koap/src/commonMain/kotlin/Message.kt
@@ -303,8 +303,8 @@ sealed class Message {
              * - `1` (deregister) removes the entry from the list, if present.
              */
             sealed class Registration {
-                object Register : Registration()
-                object Deregister : Registration()
+                data object Register : Registration()
+                data object Deregister : Registration()
             }
 
             /**