diff --git a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/PreferenceObjectBasedNotificationSetTest.java b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/PreferenceObjectBasedNotificationSetTest.java
index ab11ec7d336..20e8b8647de 100644
--- a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/PreferenceObjectBasedNotificationSetTest.java
+++ b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/PreferenceObjectBasedNotificationSetTest.java
@@ -31,16 +31,16 @@ public class PreferenceObjectBasedNotificationSetTest {
 
     private UserStoreImpl store;
     
-    private String user1 = "me";
-    private String user2 = "somebody_else";
-    private String mail = "anonymous@sapsailing.com";
+    private static final String user1 = "me";
+    private static final String user2 = "somebody_else";
+    private static final String mail = "anonymous@sapsailing.com";
     
-    private JavaIoSerializablePreferenceConverter<HashSet<String>> prefConverter = new JavaIoSerializablePreferenceConverter<>();
-    private String prefKey = "prefKey";
-    private String otherPrefKey = "otherPrefKey";
-    private HashSet<String> values1 = values(A, B);
-    private HashSet<String> values2 = values(B, C);
-    private HashSet<String> allValues = values(A, B, C);
+    private static final JavaIoSerializablePreferenceConverter<HashSet<String>> prefConverter = new JavaIoSerializablePreferenceConverter<>();
+    private static final String prefKey = "prefKey";
+    private static final String otherPrefKey = "otherPrefKey";
+    private static final HashSet<String> values1 = values(A, B);
+    private static final HashSet<String> values2 = values(B, C);
+    private static final HashSet<String> allValues = values(A, B, C);
 
     @Before
     public void setUp() throws UnknownHostException, MongoException {
diff --git a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserPreferenceObjectAndConverterTest.java b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserPreferenceObjectAndConverterTest.java
index 01a30f1be44..e07beeba608 100644
--- a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserPreferenceObjectAndConverterTest.java
+++ b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserPreferenceObjectAndConverterTest.java
@@ -21,16 +21,16 @@ public class UserPreferenceObjectAndConverterTest {
     private UserStoreImpl store;
 
     private final String email = "anonymous@sapsailing.com";
-    private String user1 = "me";
-    private String user2 = "somebody_else";
+    private static final String user1 = "me";
+    private static final String user2 = "somebody_else";
     
-    private JavaIoSerializablePreferenceConverter<SimplePreferenceForSerialization> prefConverter = new JavaIoSerializablePreferenceConverter<>();
-    private String prefKey1 = "prefKey1";
-    private SimplePreferenceForSerialization pref1 = new SimplePreferenceForSerialization("test12345", false, 432.567);
-    private String serializedPref1 = prefConverter.toPreferenceString(pref1);
-    private String prefKey2 = "prefKey2";
-    private SimplePreferenceForSerialization pref2 = new SimplePreferenceForSerialization("some sailing value", true, 9.87654321);
-    private String serializedPref2 = prefConverter.toPreferenceString(pref2);
+    private static final JavaIoSerializablePreferenceConverter<SimplePreferenceForSerialization> prefConverter = new JavaIoSerializablePreferenceConverter<>();
+    private static final String prefKey1 = "prefKey1";
+    private static final SimplePreferenceForSerialization pref1 = new SimplePreferenceForSerialization("test12345", false, 432.567);
+    private static final String serializedPref1 = prefConverter.toPreferenceString(pref1);
+    private static final String prefKey2 = "prefKey2";
+    private static final SimplePreferenceForSerialization pref2 = new SimplePreferenceForSerialization("some sailing value", true, 9.87654321);
+    private static final String serializedPref2 = prefConverter.toPreferenceString(pref2);
 
     @Before
     public void setUp() throws UnknownHostException, MongoException {
@@ -96,7 +96,7 @@ public class UserPreferenceObjectAndConverterTest {
         store.registerPreferenceConverter(prefKey1, prefConverter);
         store.setPreferenceObject(user1, prefKey1, pref1);
         store.unsetPreference(user1, prefKey1);
-        Assert.assertEquals(null, store.getPreferenceObject(user1, prefKey1));
+        Assert.assertNull(store.getPreferenceObject(user1, prefKey1));
     }
     
     @Test
@@ -104,7 +104,7 @@ public class UserPreferenceObjectAndConverterTest {
         store.registerPreferenceConverter(prefKey1, prefConverter);
         store.setPreferenceObject(user1, prefKey1, pref1);
         store.setPreferenceObject(user1, prefKey1, null);
-        Assert.assertEquals(null, store.getPreferenceObject(user1, prefKey1));
+        Assert.assertNull(store.getPreferenceObject(user1, prefKey1));
     }
     
     /**
diff --git a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserStoreTest.java b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserStoreTest.java
index 48d3cc91552..0f6b1531b99 100644
--- a/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserStoreTest.java
+++ b/java/com.sap.sse.security.test/src/com/sap/sse/security/test/UserStoreTest.java
@@ -42,6 +42,9 @@ public class UserStoreTest {
         assertEquals(username, newUserStore.getUserByAccessToken(accessToken).getName());
     }
     
+    /**
+     * There was a bug that caused the preferences not to be removed when a user was deleted.
+     */
     @Test
     public void testDeleteUserWithPreference() throws UserManagementException {
         userStore.unsetPreference(username, prefKey);