diff --git a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/jersey/JerseyEndpointResourceFactory.java b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/jersey/JerseyEndpointResourceFactory.java
index cf27addf3a1..4f9bb5d2537 100644
--- a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/jersey/JerseyEndpointResourceFactory.java
+++ b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/jersey/JerseyEndpointResourceFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,6 +55,7 @@ import org.springframework.boot.actuate.endpoint.web.WebEndpointResponse;
 import org.springframework.boot.actuate.endpoint.web.WebOperation;
 import org.springframework.boot.actuate.endpoint.web.WebOperationRequestPredicate;
 import org.springframework.boot.actuate.endpoint.web.WebServerNamespace;
+import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.util.AntPathMatcher;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
@@ -189,8 +190,10 @@ public class JerseyEndpointResourceFactory {
 		}
 
 		@SuppressWarnings("unchecked")
-		private Map<String, Object> extractBodyArguments(ContainerRequestContext data) {
-			Map<String, Object> entity = ((ContainerRequest) data).readEntity(Map.class);
+		private Map<String, String> extractBodyArguments(ContainerRequestContext data) {
+			Map<String, String> entity = ((ContainerRequest) data).readEntity(Map.class,
+					new ParameterizedTypeReference<Map<String, String>>() {
+					}.getType());
 			return (entity != null) ? entity : Collections.emptyMap();
 		}
 
diff --git a/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/annotation/AbstractWebEndpointIntegrationTests.java b/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/annotation/AbstractWebEndpointIntegrationTests.java
index cc2286270fd..dbdf5569ca4 100644
--- a/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/annotation/AbstractWebEndpointIntegrationTests.java
+++ b/spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/annotation/AbstractWebEndpointIntegrationTests.java
@@ -314,6 +314,24 @@ public abstract class AbstractWebEndpointIntegrationTests<T extends Configurable
 		});
 	}
 
+	@Test
+	void writeOperationWithListOfValuesIsRejected() {
+		load(TestEndpointConfiguration.class, (client) -> {
+			Map<String, Object> body = new HashMap<>();
+			body.put("generic", List.of("one", "two"));
+			client.post().uri("/test/one").bodyValue(body).exchange().expectStatus().isBadRequest();
+		});
+	}
+
+	@Test
+	void writeOperationWithNestedValueIsRejected() {
+		load(TestEndpointConfiguration.class, (client) -> {
+			Map<String, Object> body = new HashMap<>();
+			body.put("generic", Map.of("nested", "one"));
+			client.post().uri("/test/one").bodyValue(body).exchange().expectStatus().isBadRequest();
+		});
+	}
+
 	@Test
 	void writeOperationWithVoidResponse() {
 		load(VoidWriteResponseEndpointConfiguration.class, (context, client) -> {
@@ -968,6 +986,11 @@ public abstract class AbstractWebEndpointIntegrationTests<T extends Configurable
 			this.endpointDelegate.write(foo, bar);
 		}
 
+		@WriteOperation
+		void writeGeneric(@Selector String part, Object generic) {
+			this.endpointDelegate.write(generic.toString(), generic.toString());
+		}
+
 		@DeleteOperation
 		Map<String, Object> deletePart(@Selector String part) {
 			return Collections.singletonMap("part", part);