diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 5bf599c24..c064e0e0a 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -14,7 +14,7 @@ jobs:
     - name: Set up Java
       uses: actions/setup-java@v4
       with:
-        java-version: '17'
+        java-version: '21'
         distribution: 'temurin'
         cache: 'maven'
       
diff --git a/com.archimatetool.editor.product/archi.target b/com.archimatetool.editor.product/archi.target
index e301a7b4b..10970a539 100644
--- a/com.archimatetool.editor.product/archi.target
+++ b/com.archimatetool.editor.product/archi.target
@@ -10,8 +10,8 @@
         <unit id="org.eclipse.jgit.ssh.apache.feature.group" version="6.10.0.202406032230-r"/>
     </location>
     <location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
-        <repository location="https://download.eclipse.org/tools/orbit/simrel/orbit-aggregation/release/4.32.0"/>
-        <unit id="org.mockito.mockito-core" version="5.12.0"/>
+        <repository location="https://download.eclipse.org/tools/orbit/simrel/orbit-aggregation/2024-12"/>
+        <unit id="org.mockito.mockito-core" version="5.14.2"/>
     </location>
 </locations>
 </target>
\ No newline at end of file
diff --git a/tests/com.archimatetool.testsupport/META-INF/MANIFEST.MF b/tests/com.archimatetool.testsupport/META-INF/MANIFEST.MF
index 1b7782e4c..6eae81d60 100644
--- a/tests/com.archimatetool.testsupport/META-INF/MANIFEST.MF
+++ b/tests/com.archimatetool.testsupport/META-INF/MANIFEST.MF
@@ -7,6 +7,7 @@ Bundle-Vendor: Archi
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Eclipse-BundleShape: dir
 Export-Package: com.archimatetool.tests
+Import-Package: org.mockito
 Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.ui
 Bundle-ClassPath: .
diff --git a/tests/pom.xml b/tests/pom.xml
index 30fe8dbfd..c1d13cad5 100644
--- a/tests/pom.xml
+++ b/tests/pom.xml
@@ -12,13 +12,34 @@
 
     <artifactId>com.archimatetool.testing</artifactId>
     <packaging>pom</packaging>
+    
+    <properties>
+        <!-- Mockito/ByeBuddy needs this on Java 21+ -->
+        <mockito.args>-Xshare:off -javaagent:${org.mockito:mockito-core:jar}</mockito.args>
+        <!-- <tycho.testArgLine> is passed as <argLine> to tycho-surefire-plugin -->
+        <tycho.testArgLine>${mockito.args}</tycho.testArgLine>
+    </properties>
+    
+    <profiles>
+        <profile>
+            <id>osx</id>
+            <activation>
+                <os>
+                    <family>mac</family>
+                </os>
+            </activation>
+            <properties>
+                <tycho.testArgLine>-XstartOnFirstThread ${mockito.args}</tycho.testArgLine>
+            </properties>
+        </profile>
+    </profiles>
 
     <!-- Orbit p2 repo provides Mockito and latest JUnit for tests -->
     <repositories>
         <repository>
             <id>Orbit</id>
             <layout>p2</layout>
-            <url>https://download.eclipse.org/tools/orbit/simrel/orbit-aggregation/release/4.32.0</url>
+            <url>https://download.eclipse.org/tools/orbit/simrel/orbit-aggregation/2024-12</url>
         </repository>
     </repositories>
 
@@ -43,6 +64,20 @@
 
     <build>
         <plugins>
+            <!-- Add this so we can resolve ${org.mockito:mockito-core:jar} -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>3.8.1</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>properties</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            
             <plugin>
                 <groupId>org.eclipse.tycho</groupId>
                 <artifactId>tycho-surefire-plugin</artifactId>
@@ -56,30 +91,4 @@
             </plugin>
         </plugins>
     </build>
-	
-    <profiles>
-        <profile>
-            <id>osx</id>
-            <activation>
-                <os>
-                    <family>mac</family>
-                </os>
-            </activation>
-            <build>
-                <pluginManagement>
-                    <plugins>
-                        <plugin>
-                            <groupId>org.eclipse.tycho</groupId>
-                            <artifactId>tycho-surefire-plugin</artifactId>
-                            <version>${tycho-version}</version>
-                            <configuration>
-                                <argLine>-XstartOnFirstThread</argLine>
-                            </configuration>
-                        </plugin>
-                    </plugins>
-                </pluginManagement>
-            </build>
-        </profile>
-    </profiles>
-
 </project>