diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/anyof_class.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/anyof_class.mustache
index a8fe1d77cae2..b37ceb585a7a 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/anyof_class.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/anyof_class.mustache
@@ -85,7 +85,9 @@ import java.io.IOException
  *
  */
 {{#parcelizeModels}}
+{{^kotlinx_serialization}}
 @Parcelize
+{{/kotlinx_serialization}}
 {{/parcelizeModels}}
 {{^generateOneOfAnyOfWrappers}}
 {{#multiplatform}}{{^discriminator}}@Serializable{{/discriminator}}{{/multiplatform}}{{#kotlinx_serialization}}{{#serializableModel}}@KSerializable{{/serializableModel}}{{^serializableModel}}@Serializable{{/serializableModel}}{{/kotlinx_serialization}}{{#moshi}}{{#moshiCodeGen}}@JsonClass(generateAdapter = true){{/moshiCodeGen}}{{/moshi}}{{#jackson}}{{#discriminator}}{{>typeInfoAnnotation}}{{/discriminator}}{{/jackson}}
@@ -102,11 +104,12 @@ import java.io.IOException
 
 {{#kotlinx_serialization}}
 {{#generateOneOfAnyOfWrappers}}
-{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}} {
+{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}}{{#parcelizeModels}} : Parcelable{{/parcelizeModels}} {
 {{#composedSchemas}}
 {{#anyOf}}
 {{^vendorExtensions.x-duplicated-data-type}}
-    @JvmInline
+{{#parcelizeModels}}    @Parcelize
+{{/parcelizeModels}}    @JvmInline
     {{#explicitApi}}public {{/explicitApi}}value class {{#fnToValueClassName}}{{{dataType}}}{{/fnToValueClassName}}({{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}val value: {{{dataType}}}) : {{classname}}
 
 {{/vendorExtensions.x-duplicated-data-type}}
diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache
index 73ee7570ec86..a920aea2e00c 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/oneof_class.mustache
@@ -96,7 +96,9 @@ import java.io.IOException
  *
  */
 {{#parcelizeModels}}
+{{^kotlinx_serialization}}
 @Parcelize
+{{/kotlinx_serialization}}
 {{/parcelizeModels}}
 {{^generateOneOfAnyOfWrappers}}
 {{^discriminator}}
@@ -119,9 +121,10 @@ import java.io.IOException
 {{>additionalModelTypeAnnotations}}
 {{#kotlinx_serialization}}
 {{#discriminator}}
-{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}} {
+{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}}{{#parcelizeModels}} : Parcelable{{/parcelizeModels}} {
 {{#discriminator.mappedModels}}
-    @JvmInline
+{{#parcelizeModels}}    @Parcelize
+{{/parcelizeModels}}    @JvmInline
     {{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}} value class {{#fnToOneOfWrapperName}}{{mappingName}}{{/fnToOneOfWrapperName}}(val value: {{modelName}}) : {{classname}}
 
 {{/discriminator.mappedModels}}
@@ -164,11 +167,12 @@ import java.io.IOException
 }
 {{/discriminator}}
 {{^discriminator}}
-{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}} {
+{{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}sealed interface {{classname}}{{#parcelizeModels}} : Parcelable{{/parcelizeModels}} {
 {{#composedSchemas}}
 {{#oneOf}}
 {{^vendorExtensions.x-duplicated-data-type}}
-    @JvmInline
+{{#parcelizeModels}}    @Parcelize
+{{/parcelizeModels}}    @JvmInline
     {{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}value class {{#fnToValueClassName}}{{{dataType}}}{{/fnToValueClassName}}({{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}val value: {{{dataType}}}) : {{classname}}
 
 {{/vendorExtensions.x-duplicated-data-type}}