diff --git a/spring-rest-http/src/main/java/com/baeldung/requestmapping/FooMappingExamplesController.java b/spring-rest-http/src/main/java/com/baeldung/requestmapping/FooMappingExamplesController.java
index 90012ed05411..543ba76273b3 100644
--- a/spring-rest-http/src/main/java/com/baeldung/requestmapping/FooMappingExamplesController.java
+++ b/spring-rest-http/src/main/java/com/baeldung/requestmapping/FooMappingExamplesController.java
@@ -1,6 +1,8 @@
 package com.baeldung.requestmapping;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -103,8 +105,8 @@ public String putAndPostFoos() {
     // --- Ambiguous Mapping
  
     @GetMapping(value = "foos/duplicate" )
-    public String duplicate() {
-        return "Duplicate";
+    public ResponseEntity<String> duplicate() {
+        return new ResponseEntity<>("Duplicate", HttpStatus.OK);
     }
     
     // uncomment for exception of type java.lang.IllegalStateException: Ambiguous mapping
@@ -114,14 +116,14 @@ public String duplicate() {
     // return "Duplicate";
     // }
     
-    @GetMapping(value = "foos/duplicate/xml", produces = MediaType.APPLICATION_XML_VALUE)
-    public String duplicateXml() {
-        return "Duplicate Xml";
+    @GetMapping(value = "foos/duplicate", produces = MediaType.APPLICATION_XML_VALUE)
+    public ResponseEntity<String> duplicateXml() {
+        return new ResponseEntity<>("<message>Duplicate</message>", HttpStatus.OK);
     }
      
-    @GetMapping(value = "foos/duplicate/json", produces = MediaType.APPLICATION_JSON_VALUE)
-    public String duplicateJson() {
-        return "Duplicate Json";
+    @GetMapping(value = "foos/duplicate", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<String> duplicateJson() {
+        return new ResponseEntity<>("{\"message\":\"Duplicate\"}", HttpStatus.OK);
     }
 
 }
\ No newline at end of file
diff --git a/spring-rest-http/src/test/java/com/baeldung/requestmapping/FooMappingExamplesControllerUnitTest.java b/spring-rest-http/src/test/java/com/baeldung/requestmapping/FooMappingExamplesControllerUnitTest.java
new file mode 100644
index 000000000000..388b4b735475
--- /dev/null
+++ b/spring-rest-http/src/test/java/com/baeldung/requestmapping/FooMappingExamplesControllerUnitTest.java
@@ -0,0 +1,35 @@
+package com.baeldung.requestmapping;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
+
+@RunWith(SpringRunner.class)
+@WebMvcTest(FooMappingExamplesController.class)
+public class FooMappingExamplesControllerUnitTest {
+
+    @Autowired
+    private MockMvc mvc;
+
+    @Test
+    public void givenAcceptsJson_whenGetDuplicate_thenJsonResponseReturned() throws Exception {
+        mvc.perform(get("/ex/foos/duplicate")
+            .accept(MediaType.APPLICATION_JSON))
+            .andExpect(status().isOk())
+            .andExpect(content().string("{\"message\":\"Duplicate\"}"));
+    }
+
+    @Test
+    public void givenAcceptsXml_whenGetDuplicate_thenXmlResponseReturned() throws Exception {
+        mvc.perform(get("/ex/foos/duplicate")
+            .accept(MediaType.APPLICATION_XML))
+            .andExpect(status().isOk())
+            .andExpect(content().string("<message>Duplicate</message>"));
+    }
+}