diff --git a/samples/xapi-server/src/test/java/dev/learning/xapi/samples/xapiserver/StatementsControllerTest.java b/samples/xapi-server/src/test/java/dev/learning/xapi/samples/xapiserver/StatementsControllerTest.java
index 2109fe2e..b4cb23ac 100644
--- a/samples/xapi-server/src/test/java/dev/learning/xapi/samples/xapiserver/StatementsControllerTest.java
+++ b/samples/xapi-server/src/test/java/dev/learning/xapi/samples/xapiserver/StatementsControllerTest.java
@@ -12,7 +12,7 @@
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
-import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.servlet.MockMvc;
 
@@ -30,7 +30,7 @@ class StatementControllerTest {
   @Autowired
   private MockMvc mvc;
 
-  @MockBean
+  @MockitoBean
   private StatementService statementService;
 
   @Test
diff --git a/xapi-model/src/main/java/dev/learning/xapi/model/LanguageMap.java b/xapi-model/src/main/java/dev/learning/xapi/model/LanguageMap.java
index b94824a7..abf2d86b 100644
--- a/xapi-model/src/main/java/dev/learning/xapi/model/LanguageMap.java
+++ b/xapi-model/src/main/java/dev/learning/xapi/model/LanguageMap.java
@@ -29,7 +29,7 @@ public class LanguageMap extends LinkedHashMap<Locale, String> {
   /**
    * Cached undefined locale instance to avoid repeated object creation.
    */
-  private static final Locale UNDEFINED_LOCALE = new Locale("und");
+  private static final Locale UNDEFINED_LOCALE = Locale.forLanguageTag("und");
 
   /**
    * Constructs an empty LanguageMap.
diff --git a/xapi-model/src/test/java/dev/learning/xapi/model/LanguageMapTests.java b/xapi-model/src/test/java/dev/learning/xapi/model/LanguageMapTests.java
index b1a31c5d..f7530c30 100644
--- a/xapi-model/src/test/java/dev/learning/xapi/model/LanguageMapTests.java
+++ b/xapi-model/src/test/java/dev/learning/xapi/model/LanguageMapTests.java
@@ -115,7 +115,7 @@ void givenUsAndUndKeyWhenGettingGermanValueThenValueIsUnd() {
 
     // Given US And UND Key
     languageMap.put(Locale.US, "Color");
-    languageMap.put(new Locale("und"), "Colour");
+    languageMap.put(Locale.forLanguageTag("und"), "Colour");
 
     // When Getting German Value
     final var value = languageMap.get(LanguageRange.parse("de"));
diff --git a/xapi-model/src/test/java/dev/learning/xapi/model/VerbTests.java b/xapi-model/src/test/java/dev/learning/xapi/model/VerbTests.java
index f8b137a7..c8a3636c 100644
--- a/xapi-model/src/test/java/dev/learning/xapi/model/VerbTests.java
+++ b/xapi-model/src/test/java/dev/learning/xapi/model/VerbTests.java
@@ -142,7 +142,7 @@ void givenVerbIsConstructedWithIdAndNameWhenGettingDisplayForLocaleUNDThenResult
     final var verb = new Verb("http://adlnet.gov/expapi/verbs/answered", "answered");
 
     // When Getting Display For Locale UND
-    final var result = verb.getDisplay().get(Locale.forLanguageTag("UND"));
+    final var result = verb.getDisplay().get(Locale.forLanguageTag("und"));
 
     // Then Result Is Expected
     assertThat(result, is("answered"));