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 dfc48ab336b0..a8fe1d77cae2 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
@@ -107,7 +107,7 @@ import java.io.IOException
 {{#anyOf}}
 {{^vendorExtensions.x-duplicated-data-type}}
     @JvmInline
-    {{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}value class {{#fnToValueClassName}}{{{dataType}}}{{/fnToValueClassName}}(val value: {{{dataType}}}) : {{classname}}
+    {{#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}}
 {{/anyOf}}
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 80b3baa97f60..73ee7570ec86 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
@@ -169,7 +169,7 @@ import java.io.IOException
 {{#oneOf}}
 {{^vendorExtensions.x-duplicated-data-type}}
     @JvmInline
-    {{#nonPublicApi}}internal {{/nonPublicApi}}{{^nonPublicApi}}{{#explicitApi}}public {{/explicitApi}}{{/nonPublicApi}}value class {{#fnToValueClassName}}{{{dataType}}}{{/fnToValueClassName}}(val value: {{{dataType}}}) : {{classname}}
+    {{^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}}
 {{/oneOf}}
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
index 23f98e3c443e..e86ce4e069ac 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java
@@ -685,6 +685,57 @@ public void anyOfPrimitiveKotlinxSerialization() throws IOException {
         TestUtils.assertFileContains(parentModelKt, "val id: ObjectWithComplexAnyOfId?");
     }
 
+    @Test(description = "generate oneOf/anyOf wrappers with explicit API mode using kotlinx_serialization")
+    public void oneOfAnyOfKotlinxSerializationExplicitApi() throws IOException {
+        File output = generateKotlinxOneOfAnyOf(new HashMap<>() {{ put(KotlinClientCodegen.EXPLICIT_API, true); }});
+        // value class nested inside sealed interface: public is valid, internal is not
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexOneOfId"),
+                "public value class StringValue(public val value: kotlin.String) : ObjectWithComplexOneOfId");
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexAnyOfId"),
+                "public value class StringValue(public val value: kotlin.String) : ObjectWithComplexAnyOfId");
+    }
+
+    @Test(description = "generate oneOf/anyOf wrappers with non-public API mode using kotlinx_serialization")
+    public void oneOfAnyOfKotlinxSerializationNonPublicApi() throws IOException {
+        File output = generateKotlinxOneOfAnyOf(new HashMap<>() {{ put(CodegenConstants.NON_PUBLIC_API, true); }});
+        // Kotlin doesn't allow internal subclasses of internal interfaces, make sure subclasses are generated correctly
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexOneOfId"),
+                "internal sealed interface ObjectWithComplexOneOfId");
+        TestUtils.assertFileNotContains(modelPath(output, "ObjectWithComplexOneOfId"),
+                "internal value class StringValue");
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexOneOfId"),
+                "value class StringValue(internal val value: kotlin.String) : ObjectWithComplexOneOfId");
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexAnyOfId"),
+                "internal sealed interface ObjectWithComplexAnyOfId");
+        TestUtils.assertFileNotContains(modelPath(output, "ObjectWithComplexAnyOfId"),
+                "internal value class StringValue");
+        TestUtils.assertFileContains(modelPath(output, "ObjectWithComplexAnyOfId"),
+                "value class StringValue(internal val value: kotlin.String) : ObjectWithComplexAnyOfId");
+    }
+
+    private File generateKotlinxOneOfAnyOf(Map<String, Object> extraProps) throws IOException {
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+        Map<String, Object> props = new HashMap<>();
+        props.put(CodegenConstants.SERIALIZATION_LIBRARY, "kotlinx_serialization");
+        props.put(GENERATE_ONEOF_ANYOF_WRAPPERS, true);
+        props.putAll(extraProps);
+        new DefaultGenerator()
+                .opts(new CodegenConfigurator()
+                        .setGeneratorName("kotlin")
+                        .setLibrary("jvm-retrofit2")
+                        .setAdditionalProperties(props)
+                        .setInputSpec("src/test/resources/3_0/issue_19942.json")
+                        .setOutputDir(output.getAbsolutePath().replace("\\", "/"))
+                        .toClientOptInput())
+                .generate();
+        return output;
+    }
+
+    private static Path modelPath(File output, String modelName) {
+        return Paths.get(output + "/src/main/kotlin/org/openapitools/client/models/" + modelName + ".kt");
+    }
+
     @Test(description = "generate polymorphic jackson model")
     public void polymorphicJacksonSerialization() throws IOException {
         File output = Files.createTempDirectory("test").toFile();