diff --git a/model/src/test/java/org/cloudfoundry/identity/uaa/scim/ScimUserTests.java b/model/src/test/java/org/cloudfoundry/identity/uaa/scim/ScimUserTests.java
index ae0bb3d8e8c..c590f564585 100644
--- a/model/src/test/java/org/cloudfoundry/identity/uaa/scim/ScimUserTests.java
+++ b/model/src/test/java/org/cloudfoundry/identity/uaa/scim/ScimUserTests.java
@@ -827,6 +827,14 @@ public void testPatchActive() {
         assertTrue(patchUser.isActive());
     }
 
+    @Test
+    public void testScimUserAliasDeserialization() {
+        user.setAliasId("aliasId");
+        user.setAliasZid("custom");
+        String staticJson = "{\"id\":\"id\",\"externalId\":\"\",\"meta\":{\"version\":0},\"userName\":\"uname\",\"name\":{\"formatted\":\"gname fname\",\"familyName\":\"fname\",\"givenName\":\"gname\"},\"emails\":[{\"value\":\"test@example.org\",\"primary\":false}],\"phoneNumbers\":[{\"value\":\"0123456789\"}],\"displayName\":\"display\",\"title\":\"title\",\"locale\":\"en.UTF-8\",\"active\":true,\"verified\":true,\"origin\":\"\",\"aliasZid\":\"custom\",\"aliasId\":\"aliasId\",\"password\":\"password\",\"schemas\":[\"urn:scim:schemas:core:1.0\"]}";
+        assertEquals(user, JsonUtils.readValue(staticJson, ScimUser.class));
+    }
+
     @Test
     public void testPatchVerified() {
         user.setVerified(false);
diff --git a/server/src/test/java/org/cloudfoundry/identity/uaa/alias/EntityAliasHandlerValidationTest.java b/server/src/test/java/org/cloudfoundry/identity/uaa/alias/EntityAliasHandlerValidationTest.java
index f4a44d3063e..6552d38f144 100644
--- a/server/src/test/java/org/cloudfoundry/identity/uaa/alias/EntityAliasHandlerValidationTest.java
+++ b/server/src/test/java/org/cloudfoundry/identity/uaa/alias/EntityAliasHandlerValidationTest.java
@@ -3,6 +3,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.cloudfoundry.identity.uaa.alias.EntityAliasHandlerValidationTest.NoExistingAliasBase.ExistingEntityArgument.ENTITY_WITH_EMPTY_ALIAS_PROPS;
+import static org.junit.Assert.assertFalse;
 
 import java.util.UUID;
 import java.util.stream.Stream;
@@ -129,6 +130,12 @@ final void shouldReturnFalse_UpdatesOfEntitiesWithExistingAliasForbidden() {
             requestBody = buildEntityWithAliasProps(null, null);
             assertThat(aliasHandler.aliasPropertiesAreValid(requestBody, existingEntity)).isFalse();
         }
+
+        @Test
+        final void shouldReturnFalse_DefaultSetting() {
+            AliasEntitiesConfig aliasEntitiesConfig = new AliasEntitiesConfig();
+            assertFalse(aliasEntitiesConfig.aliasEntitiesEnabled(false));
+        }
     }
 
     protected abstract class ExistingAlias_AliasFeatureEnabled extends Base {
diff --git a/server/src/test/java/org/cloudfoundry/identity/uaa/scim/endpoints/ScimUserEndpointsAliasTests.java b/server/src/test/java/org/cloudfoundry/identity/uaa/scim/endpoints/ScimUserEndpointsAliasTests.java
index 4321c879019..f77ab48f9f3 100644
--- a/server/src/test/java/org/cloudfoundry/identity/uaa/scim/endpoints/ScimUserEndpointsAliasTests.java
+++ b/server/src/test/java/org/cloudfoundry/identity/uaa/scim/endpoints/ScimUserEndpointsAliasTests.java
@@ -13,6 +13,7 @@
 import org.cloudfoundry.identity.uaa.scim.ScimUserAliasHandler;
 import org.cloudfoundry.identity.uaa.scim.ScimUserProvisioning;
 import org.cloudfoundry.identity.uaa.scim.exception.ScimException;
+import org.cloudfoundry.identity.uaa.scim.exception.ScimResourceConflictException;
 import org.cloudfoundry.identity.uaa.scim.validate.PasswordValidator;
 import org.cloudfoundry.identity.uaa.security.IsSelfCheck;
 import org.cloudfoundry.identity.uaa.util.AlphanumericRandomValueStringGenerator;
@@ -26,6 +27,7 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.dao.OptimisticLockingFailureException;
 import org.springframework.http.HttpStatus;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
@@ -123,7 +125,7 @@ void setUp() {
 
         lenient().when(transactionTemplate.execute(any())).then(invocationOnMock -> {
             final TransactionCallback<?> callback = invocationOnMock.getArgument(0);
-            return callback.doInTransaction(mock(TransactionStatus.class));
+            return callback != null ? callback.doInTransaction(mock(TransactionStatus.class)) : null;
         });
     }
 
@@ -177,6 +179,21 @@ void shouldThrow_WhenAliasPropertiesAreInvalid() {
             assertThat(exception.getStatus()).isEqualTo(HttpStatus.BAD_REQUEST);
         }
 
+        @Test
+        void shouldThrow_WhenAliasIsNotPresent() {
+            final ScimUser user = buildScimUser(UAA, origin);
+
+            when(scimUserAliasHandler.aliasPropertiesAreValid(user, null)).thenReturn(true);
+            when(scimUserAliasHandler.ensureConsistencyOfAliasEntity(user, null)).thenReturn(null);
+
+            final MockHttpServletRequest req = new MockHttpServletRequest();
+            final MockHttpServletResponse res = new MockHttpServletResponse();
+            final IllegalStateException exception = assertThrows(IllegalStateException.class, () ->
+                scimUserEndpoints.createUser(user, req, res)
+            );
+            assertThat(exception.getMessage()).isEqualTo("The persisted user is not present after handling the alias.");
+        }
+
         @Test
         void shouldReturnOriginalUser() {
             final ScimUser user = buildScimUser(UAA, origin);
@@ -246,6 +263,28 @@ void shouldThrow_IfAliasPropertiesAreInvalid() {
             assertThat(exception.getStatus()).isEqualTo(HttpStatus.BAD_REQUEST);
         }
 
+        @Test
+        void shouldThrow_IfAliasIsLocked() {
+            when(scimUserAliasHandler.aliasPropertiesAreValid(originalUser, existingOriginalUser))
+                .thenReturn(true);
+            when(transactionTemplate.execute(any())).then(invocationOnMock -> {
+                throw new OptimisticLockingFailureException("The alias is locked.");
+            });
+
+            final ScimResourceConflictException exception = assertThrows(ScimResourceConflictException.class, () ->
+                scimUserEndpoints.updateUser(
+                    originalUser,
+                    originalUser.getId(),
+                    "*",
+                    new MockHttpServletRequest(),
+                    new MockHttpServletResponse(),
+                    null
+                )
+            );
+            assertThat(exception.getMessage()).isEqualTo("The alias is locked.");
+            assertThat(exception.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+        }
+
         @Test
         void shouldAlsoUpdateAliasUserIfPresent() {
             when(scimUserAliasHandler.aliasPropertiesAreValid(originalUser, existingOriginalUser))
@@ -467,6 +506,20 @@ void shouldThrowException_IfUserHasExistingAlias() {
                         .isEqualTo("Could not delete user with alias since alias entities are disabled.");
                 assertThat(exception.getHttpStatus()).isEqualTo(HttpStatus.BAD_REQUEST.value());
             }
+
+            @Test
+            void shouldDeleteUserIfPresent() {
+                ScimUser originalUser = buildScimUser("123456789", "uaa");
+                when(scimUserProvisioning.retrieve(any(), any())).thenReturn(originalUser);
+                final ScimUser response = scimUserEndpoints.deleteUser(
+                    "12345678",
+                    null,
+                    new MockHttpServletRequest(),
+                    new MockHttpServletResponse()
+                );
+
+                assertScimUsersAreEqual(response, originalUser);
+            }
         }
     }