diff --git a/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/MockMvcWebClientBuilderTests.java b/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/MockMvcWebClientBuilderTests.java
index c8e4b09600..dabaa5c851 100644
--- a/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/MockMvcWebClientBuilderTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/MockMvcWebClientBuilderTests.java
@@ -139,7 +139,7 @@ public class MockMvcWebClientBuilderTests {
 
 	@RestController
 	static class CookieController {
-		@RequestMapping("/")
+		@RequestMapping(value="/", produces="text/plain")
 		public String cookie(@CookieValue("cookie") String cookie) {
 			return cookie;
 		}
diff --git a/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/webdriver/MockMvcHtmlUnitDriverBuilderTests.java b/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/webdriver/MockMvcHtmlUnitDriverBuilderTests.java
index ed79749b19..dfb1da856e 100644
--- a/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/webdriver/MockMvcHtmlUnitDriverBuilderTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/servlet/htmlunit/webdriver/MockMvcHtmlUnitDriverBuilderTests.java
@@ -158,7 +158,7 @@ public class MockMvcHtmlUnitDriverBuilderTests {
 
 	@RestController
 	static class CookieController {
-		@RequestMapping("/")
+		@RequestMapping(value="/", produces="text/plain")
 		public String cookie(@CookieValue("cookie") String cookie) {
 			return cookie;
 		}