diff --git a/module/spring-boot-http-codec/src/main/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfiguration.java b/module/spring-boot-http-codec/src/main/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfiguration.java
index 7adbd522221..8b25159a81d 100644
--- a/module/spring-boot-http-codec/src/main/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfiguration.java
+++ b/module/spring-boot-http-codec/src/main/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfiguration.java
@@ -55,7 +55,8 @@ import org.springframework.web.reactive.function.client.WebClient;
  * @since 4.0.0
  */
 @AutoConfiguration(afterName = { "org.springframework.boot.jackson.autoconfigure.JacksonAutoConfiguration",
-		"org.springframework.boot.jackson2.autoconfigure.Jackson2AutoConfiguration" })
+		"org.springframework.boot.jackson2.autoconfigure.Jackson2AutoConfiguration",
+		"org.springframework.boot.kotlinx.serialization.json.autoconfigure.KotlinxSerializationJsonAutoConfiguration" })
 @ConditionalOnClass({ CodecConfigurer.class, WebClient.class })
 public final class CodecsAutoConfiguration {
 
diff --git a/module/spring-boot-http-codec/src/test/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfigurationTests.java b/module/spring-boot-http-codec/src/test/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfigurationTests.java
index 2bb25145005..8463f8dcd28 100644
--- a/module/spring-boot-http-codec/src/test/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfigurationTests.java
+++ b/module/spring-boot-http-codec/src/test/java/org/springframework/boot/http/codec/autoconfigure/CodecsAutoConfigurationTests.java
@@ -27,6 +27,7 @@ import tools.jackson.databind.json.JsonMapper;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.http.codec.CodecCustomizer;
+import org.springframework.boot.kotlinx.serialization.json.autoconfigure.KotlinxSerializationJsonAutoConfiguration;
 import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
@@ -170,6 +171,15 @@ class CodecsAutoConfigurationTests {
 			});
 	}
 
+	@Test
+	void applyKotlinxSerializationJsonAutoConfigurationBeforeCodecsAutoConfiguration() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(KotlinxSerializationJsonAutoConfiguration.class))
+			.run((context) -> {
+				Map<String, CodecCustomizer> codecCustomizers = context.getBeansOfType(CodecCustomizer.class);
+				assertThat(codecCustomizers).containsKey("kotlinxJsonCodecCustomizer");
+			});
+	}
+
 	@SuppressWarnings("unchecked")
 	private <T> T findEncoder(AssertableApplicationContext context, Class<T> encoderClass) {
 		ServerCodecConfigurer configurer = ServerCodecConfigurer.create();