diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinDeserializers.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinDeserializers.kt
index 0a927c9a..ce8bcf4f 100644
--- a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinDeserializers.kt
+++ b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinDeserializers.kt
@@ -13,12 +13,16 @@ import com.fasterxml.jackson.databind.deser.std.StdDeserializer
 import kotlin.time.Duration as KotlinDuration
 
 object SequenceDeserializer : StdDeserializer<Sequence<*>>(Sequence::class.java) {
+    private fun readResolve(): Any = SequenceDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext): Sequence<*> {
         return ctxt.readValue(p, List::class.java).asSequence()
     }
 }
 
 object RegexDeserializer : StdDeserializer<Regex>(Regex::class.java) {
+    private fun readResolve(): Any = RegexDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext): Regex {
         val node = ctxt.readTree(p)
 
@@ -43,6 +47,8 @@ object RegexDeserializer : StdDeserializer<Regex>(Regex::class.java) {
 }
 
 object UByteDeserializer : StdDeserializer<UByte>(UByte::class.java) {
+    private fun readResolve(): Any = UByteDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext) =
         p.shortValue.asUByte() ?: throw InputCoercionException(
             p,
@@ -53,6 +59,8 @@ object UByteDeserializer : StdDeserializer<UByte>(UByte::class.java) {
 }
 
 object UShortDeserializer : StdDeserializer<UShort>(UShort::class.java) {
+    private fun readResolve(): Any = UShortDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext) =
         p.intValue.asUShort() ?: throw InputCoercionException(
             p,
@@ -63,6 +71,8 @@ object UShortDeserializer : StdDeserializer<UShort>(UShort::class.java) {
 }
 
 object UIntDeserializer : StdDeserializer<UInt>(UInt::class.java) {
+    private fun readResolve(): Any = UIntDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext) =
         p.longValue.asUInt() ?: throw InputCoercionException(
             p,
@@ -73,6 +83,8 @@ object UIntDeserializer : StdDeserializer<UInt>(UInt::class.java) {
 }
 
 object ULongDeserializer : StdDeserializer<ULong>(ULong::class.java) {
+    private fun readResolve(): Any = ULongDeserializer
+
     override fun deserialize(p: JsonParser, ctxt: DeserializationContext) =
         p.bigIntegerValue.asULong() ?: throw InputCoercionException(
             p,
diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeyDeserializers.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeyDeserializers.kt
index fdf44a65..70e2e35a 100644
--- a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeyDeserializers.kt
+++ b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeyDeserializers.kt
@@ -10,6 +10,8 @@ import com.fasterxml.jackson.databind.deser.std.StdKeyDeserializers
 // If StdKeyDeserializer is modified, need to modify this too.
 
 internal object UByteKeyDeserializer : StdKeyDeserializer(TYPE_SHORT, UByte::class.java) {
+    private fun readResolve(): Any = UByteKeyDeserializer
+
     override fun deserializeKey(key: String?, ctxt: DeserializationContext): UByte? = super.deserializeKey(key, ctxt)
         ?.let {
             (it as Short).asUByte() ?: throw InputCoercionException(
@@ -22,6 +24,8 @@ internal object UByteKeyDeserializer : StdKeyDeserializer(TYPE_SHORT, UByte::cla
 }
 
 internal object UShortKeyDeserializer : StdKeyDeserializer(TYPE_INT, UShort::class.java) {
+    private fun readResolve(): Any = UShortKeyDeserializer
+
     override fun deserializeKey(key: String?, ctxt: DeserializationContext): UShort? = super.deserializeKey(key, ctxt)
         ?.let {
             (it as Int).asUShort() ?: throw InputCoercionException(
@@ -34,6 +38,8 @@ internal object UShortKeyDeserializer : StdKeyDeserializer(TYPE_INT, UShort::cla
 }
 
 internal object UIntKeyDeserializer : StdKeyDeserializer(TYPE_LONG, UInt::class.java) {
+    private fun readResolve(): Any = UIntKeyDeserializer
+
     override fun deserializeKey(key: String?, ctxt: DeserializationContext): UInt? = super.deserializeKey(key, ctxt)
         ?.let {
             (it as Long).asUInt() ?: throw InputCoercionException(
@@ -47,6 +53,8 @@ internal object UIntKeyDeserializer : StdKeyDeserializer(TYPE_LONG, UInt::class.
 
 // kind parameter is dummy.
 internal object ULongKeyDeserializer : StdKeyDeserializer(TYPE_LONG, ULong::class.java) {
+    private fun readResolve(): Any = ULongKeyDeserializer
+
     override fun deserializeKey(key: String?, ctxt: DeserializationContext): ULong? = key?.let {
         it.toBigInteger().asULong() ?: throw InputCoercionException(
             null,
@@ -58,6 +66,8 @@ internal object ULongKeyDeserializer : StdKeyDeserializer(TYPE_LONG, ULong::clas
 }
 
 internal object KotlinKeyDeserializers : StdKeyDeserializers() {
+    private fun readResolve(): Any = KotlinKeyDeserializers
+
     override fun findKeyDeserializer(
         type: JavaType,
         config: DeserializationConfig?,
diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeySerializers.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeySerializers.kt
index 06ddb96e..c6a5d774 100644
--- a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeySerializers.kt
+++ b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinKeySerializers.kt
@@ -13,6 +13,8 @@ import java.lang.reflect.Method
 import java.lang.reflect.Modifier
 
 internal object ValueClassUnboxKeySerializer : StdSerializer<Any>(Any::class.java) {
+    private fun readResolve(): Any = ValueClassUnboxKeySerializer
+
     override fun serialize(value: Any, gen: JsonGenerator, provider: SerializerProvider) {
         val method = value::class.java.getMethod("unbox-impl")
         val unboxed = method.invoke(value)
diff --git a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinSerializers.kt b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinSerializers.kt
index 6821796a..edfe23ea 100644
--- a/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinSerializers.kt
+++ b/src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinSerializers.kt
@@ -24,21 +24,29 @@ object SequenceSerializer : StdSerializer<Sequence<*>>(Sequence::class.java) {
 }
 
 object UByteSerializer : StdSerializer<UByte>(UByte::class.java) {
+    private fun readResolve(): Any = UByteSerializer
+
     override fun serialize(value: UByte, gen: JsonGenerator, provider: SerializerProvider) =
         gen.writeNumber(value.toShort())
 }
 
 object UShortSerializer : StdSerializer<UShort>(UShort::class.java) {
+    private fun readResolve(): Any = UShortSerializer
+
     override fun serialize(value: UShort, gen: JsonGenerator, provider: SerializerProvider) =
         gen.writeNumber(value.toInt())
 }
 
 object UIntSerializer : StdSerializer<UInt>(UInt::class.java) {
+    private fun readResolve(): Any = UIntSerializer
+
     override fun serialize(value: UInt, gen: JsonGenerator, provider: SerializerProvider) =
         gen.writeNumber(value.toLong())
 }
 
 object ULongSerializer : StdSerializer<ULong>(ULong::class.java) {
+    private fun readResolve(): Any = ULongSerializer
+
     override fun serialize(value: ULong, gen: JsonGenerator, provider: SerializerProvider) {
         val longValue = value.toLong()
         when {
@@ -54,6 +62,8 @@ private fun Class<*>.getStaticJsonValueGetter(): Method? = this.declaredMethods.
 }
 
 object ValueClassUnboxSerializer : StdSerializer<Any>(Any::class.java) {
+    private fun readResolve(): Any = ValueClassUnboxSerializer
+
     override fun serialize(value: Any, gen: JsonGenerator, provider: SerializerProvider) {
         val unboxed = value::class.java.getMethod("unbox-impl").invoke(value)