diff --git a/lib/taskana-cdi-example/src/main/webapp/WEB-INF/beans.xml b/lib/taskana-cdi-example/src/main/webapp/WEB-INF/beans.xml
index e69de29bb..df8f4fd28 100644
--- a/lib/taskana-cdi-example/src/main/webapp/WEB-INF/beans.xml
+++ b/lib/taskana-cdi-example/src/main/webapp/WEB-INF/beans.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="
+      http://java.sun.com/xml/ns/javaee
+      http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
+</beans>
diff --git a/lib/taskana-core/src/test/java/org/taskana/impl/TaskServiceImplTest.java b/lib/taskana-core/src/test/java/org/taskana/impl/TaskServiceImplTest.java
index 96e03dea4..858e97aa5 100644
--- a/lib/taskana-core/src/test/java/org/taskana/impl/TaskServiceImplTest.java
+++ b/lib/taskana-core/src/test/java/org/taskana/impl/TaskServiceImplTest.java
@@ -154,7 +154,7 @@ public class TaskServiceImplTest {
 
 	@Test
 	public void should_setTheReadFlag_when_taskIsRead() throws TaskNotFoundException {
-		Task task = createUnitTestTask("1", "Unit Test Task 1", "1");
+		createUnitTestTask("1", "Unit Test Task 1", "1");
 
 		Task readTask = taskServiceImpl.setTaskRead("1", true);
 		Assert.assertTrue(readTask.isRead());
diff --git a/lib/taskana-core/src/test/java/org/taskana/impl/WorkbasketServiceImplTest.java b/lib/taskana-core/src/test/java/org/taskana/impl/WorkbasketServiceImplTest.java
index 6e2ca0549..c7c0d2b2a 100644
--- a/lib/taskana-core/src/test/java/org/taskana/impl/WorkbasketServiceImplTest.java
+++ b/lib/taskana-core/src/test/java/org/taskana/impl/WorkbasketServiceImplTest.java
@@ -96,6 +96,7 @@ public class WorkbasketServiceImplTest {
 		verify(workbasketMapper).insert(any());
 	}
 
+	@SuppressWarnings("serial")
 	@Test
 	public void should_InitializeAndStoreWorkbasket_when_WorkbasketWithDistributionTargetsIsCreated() throws NotAuthorizedException {
 		doNothing().when(workbasketMapper).insert(any());
@@ -141,6 +142,7 @@ public class WorkbasketServiceImplTest {
 		verify(workbasketMapper).update(any());
 	}
 
+	@SuppressWarnings("serial")
 	@Test
 	public void should_ReturnUpdatedWorkbasket_when_ExistingWorkbasketDistributionTargetIsChanged()
 			throws NotAuthorizedException {
@@ -252,6 +254,7 @@ public class WorkbasketServiceImplTest {
 		workbasketServiceImpl.checkAuthorization("1", WorkbasketAuthorization.READ);
 	}
 
+	@SuppressWarnings("serial")
 	@Test
 	public void should_Pass_when_OperationIsAuthorized() throws NotAuthorizedException {
 		when(taskanaEngine.getConfiguration()).thenReturn(taskanaEngineConfiguration);
diff --git a/lib/taskana-core/src/test/resources/log4j2-test.xml b/lib/taskana-core/src/test/resources/log4j2-test.xml
index db28892cb..3a985de69 100644
--- a/lib/taskana-core/src/test/resources/log4j2-test.xml
+++ b/lib/taskana-core/src/test/resources/log4j2-test.xml
@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE xml>
 <Configuration status="WARN">
 	<Appenders>
 		<Console name="Console" target="SYSTEM_OUT">
diff --git a/rest/src/main/java/org/taskana/rest/security/SampleLoginModule.java b/rest/src/main/java/org/taskana/rest/security/SampleLoginModule.java
index 3401381c7..44e6fc041 100644
--- a/rest/src/main/java/org/taskana/rest/security/SampleLoginModule.java
+++ b/rest/src/main/java/org/taskana/rest/security/SampleLoginModule.java
@@ -12,10 +12,6 @@ import javax.security.auth.spi.LoginModule;
 
 public class SampleLoginModule implements LoginModule {
 
-	private Subject subject;
-	private String password;
-	private String username;
-
 	public boolean abort() throws LoginException {
 		return true;
 	}
@@ -26,16 +22,12 @@ public class SampleLoginModule implements LoginModule {
 
 	public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState,
 			Map<String, ?> options) {
-		this.subject = subject;
 
 		try {
 			NameCallback nameCallback = new NameCallback("prompt");
 			PasswordCallback passwordCallback = new PasswordCallback("prompt", false);
 
 			callbackHandler.handle(new Callback[] { nameCallback, passwordCallback });
-
-			this.password = new String(passwordCallback.getPassword());
-			this.username = nameCallback.getName();
 		} catch (Exception e) {
 			throw new RuntimeException(e);
 		}