diff --git a/core/spring-boot-test/build.gradle b/core/spring-boot-test/build.gradle
index 3ef5e388292..64269caf640 100644
--- a/core/spring-boot-test/build.gradle
+++ b/core/spring-boot-test/build.gradle
@@ -33,6 +33,7 @@ dependencies {
 	optional("jakarta.json.bind:jakarta.json.bind-api")
 	optional("jakarta.servlet:jakarta.servlet-api")
 	optional("junit:junit")
+	optional("io.projectreactor.netty:reactor-netty-http")
 	optional("org.assertj:assertj-core")
 	optional("org.hamcrest:hamcrest-core")
 	optional("org.hamcrest:hamcrest-library")
diff --git a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java
similarity index 95%
rename from module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java
rename to core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java
index f015fcbad61..dd018a3361a 100644
--- a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java
+++ b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesBeanPostProcessor.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.web.server.test.reactor.netty;
+package org.springframework.boot.test.http.client;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanPostProcessor;
diff --git a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java
similarity index 84%
rename from module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java
rename to core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java
index 33470900473..9c4dbb0d6d0 100644
--- a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java
+++ b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.web.server.test.reactor.netty;
+package org.springframework.boot.test.http.client;
 
 import java.util.List;
 
@@ -36,12 +36,16 @@ import org.springframework.util.ClassUtils;
  */
 class DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory implements ContextCustomizerFactory {
 
-	String REACTOR_RESOURCE_FACTORY_CLASS = "org.springframework.http.client.ReactorResourceFactory";
+	private static final String REACTOR_RESOURCE_FACTORY_CLASS = "org.springframework.http.client.ReactorResourceFactory";
+
+	private static final String REACTOR_NETTY_CLASS = "reactor.netty.ReactorNetty";
 
 	@Override
 	public @Nullable ContextCustomizer createContextCustomizer(Class<?> testClass,
 			List<ContextConfigurationAttributes> configAttributes) {
-		if (ClassUtils.isPresent(this.REACTOR_RESOURCE_FACTORY_CLASS, testClass.getClassLoader())) {
+		ClassLoader classLoader = testClass.getClassLoader();
+		if (ClassUtils.isPresent(REACTOR_RESOURCE_FACTORY_CLASS, classLoader)
+				&& ClassUtils.isPresent(REACTOR_NETTY_CLASS, classLoader)) {
 			return new DisableReactorResourceFactoryGlobalResourcesContextCustomizerCustomizer();
 		}
 		return null;
diff --git a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/package-info.java b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/package-info.java
similarity index 85%
rename from module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/package-info.java
rename to core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/package-info.java
index 3a652551542..ee2f8adb887 100644
--- a/module/spring-boot-web-server-test/src/main/java/org/springframework/boot/web/server/test/reactor/netty/package-info.java
+++ b/core/spring-boot-test/src/main/java/org/springframework/boot/test/http/client/package-info.java
@@ -15,9 +15,9 @@
  */
 
 /**
- * Spring Boot support for testing Reactor Netty.
+ * Spring Boot support for HTTP client testing.
  */
 @NullMarked
-package org.springframework.boot.web.server.test.reactor.netty;
+package org.springframework.boot.test.http.client;
 
 import org.jspecify.annotations.NullMarked;
diff --git a/core/spring-boot-test/src/main/resources/META-INF/spring.factories b/core/spring-boot-test/src/main/resources/META-INF/spring.factories
index 6ab6fb5634f..74b012ead52 100644
--- a/core/spring-boot-test/src/main/resources/META-INF/spring.factories
+++ b/core/spring-boot-test/src/main/resources/META-INF/spring.factories
@@ -4,6 +4,7 @@ org.springframework.boot.test.context.ImportsContextCustomizerFactory,\
 org.springframework.boot.test.context.PropertyMappingContextCustomizerFactory,\
 org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizerFactory,\
 org.springframework.boot.test.context.filter.annotation.TypeExcludeFiltersContextCustomizerFactory,\
+org.springframework.boot.test.http.client.DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory,\
 org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory,\
 org.springframework.boot.test.web.reactive.client.WebTestClientContextCustomizerFactory,\
 org.springframework.boot.test.web.servlet.client.RestTestClientContextCustomizerFactory
diff --git a/module/spring-boot-web-server-test/src/test/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java b/core/spring-boot-test/src/test/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java
similarity index 96%
rename from module/spring-boot-web-server-test/src/test/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java
rename to core/spring-boot-test/src/test/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java
index 4dc118dd265..04baaa02a42 100644
--- a/module/spring-boot-web-server-test/src/test/java/org/springframework/boot/web/server/test/reactor/netty/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java
+++ b/core/spring-boot-test/src/test/java/org/springframework/boot/test/http/client/DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactoryTests.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.web.server.test.reactor.netty;
+package org.springframework.boot.test.http.client;
 
 import org.junit.jupiter.api.Test;
 
diff --git a/module/spring-boot-web-server-test/src/main/resources/META-INF/spring.factories b/module/spring-boot-web-server-test/src/main/resources/META-INF/spring.factories
index e19a044d420..b0f03622985 100644
--- a/module/spring-boot-web-server-test/src/main/resources/META-INF/spring.factories
+++ b/module/spring-boot-web-server-test/src/main/resources/META-INF/spring.factories
@@ -1,7 +1,3 @@
 # Environment Post Processors
 org.springframework.boot.EnvironmentPostProcessor=\
 org.springframework.boot.web.server.test.SpringBootTestRandomPortEnvironmentPostProcessor
-
-# Spring Test Context Customizer Factories
-org.springframework.test.context.ContextCustomizerFactory=\
-org.springframework.boot.web.server.test.reactor.netty.DisableReactorResourceFactoryGlobalResourcesContextCustomizerFactory