diff --git a/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/ControllerManagement.java b/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/ControllerManagement.java
index 844bbd097..e4a1e5e6b 100644
--- a/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/ControllerManagement.java
+++ b/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/ControllerManagement.java
@@ -15,7 +15,6 @@ import java.util.Map;
 import javax.persistence.EntityManager;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
-import javax.persistence.criteria.Predicate;
 import javax.persistence.criteria.Root;
 import javax.validation.constraints.NotNull;
 
@@ -212,14 +211,9 @@ public class ControllerManagement implements EnvironmentAware {
     @Modifying
     @Transactional
     @PreAuthorize(SpringEvalExpressions.IS_CONTROLLER)
-    public Target findOrRegisterTargetIfItDoesNotexist(@NotNull final String targetid, final URI address) {
-        final Specification<Target> spec = new Specification<Target>() {
-            @Override
-            public Predicate toPredicate(final Root<Target> targetRoot, final CriteriaQuery<?> query,
-                    final CriteriaBuilder cb) {
-                return cb.equal(targetRoot.get(Target_.controllerId), targetid);
-            }
-        };
+    public Target findOrRegisterTargetIfItDoesNotexist(@NotEmpty final String targetid, final URI address) {
+        final Specification<Target> spec = (targetRoot, query, cb) -> cb.equal(targetRoot.get(Target_.controllerId),
+                targetid);
 
         Target target = targetRepository.findOne(spec);
 
@@ -229,9 +223,9 @@ public class ControllerManagement implements EnvironmentAware {
             target.setName(targetid);
             return targetManagement.createTarget(target, TargetUpdateStatus.REGISTERED, System.currentTimeMillis(),
                     address);
-        } else {
-            return updateLastTargetQuery(target.getTargetInfo(), address).getTarget();
         }
+
+        return updateLastTargetQuery(target.getTargetInfo(), address).getTarget();
     }
 
     /**
diff --git a/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/TargetManagement.java b/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/TargetManagement.java
index e790d0a5e..fb824dfae 100644
--- a/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/TargetManagement.java
+++ b/hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/TargetManagement.java
@@ -27,8 +27,10 @@ import javax.persistence.criteria.JoinType;
 import javax.persistence.criteria.Order;
 import javax.persistence.criteria.Predicate;
 import javax.persistence.criteria.Root;
+import javax.validation.ConstraintViolationException;
 import javax.validation.constraints.NotNull;
 
+import org.apache.commons.lang3.StringUtils;
 import org.eclipse.hawkbit.Constants;
 import org.eclipse.hawkbit.eventbus.event.TargetTagAssigmentResultEvent;
 import org.eclipse.hawkbit.executor.AfterTransactionCommitExecutor;
@@ -931,6 +933,11 @@ public class TargetManagement {
     public Target createTarget(@NotNull final Target target, @NotNull final TargetUpdateStatus status,
             final Long lastTargetQuery, final URI address) {
 
+        if (StringUtils.isEmpty(target.getControllerId())) {
+            throw new ConstraintViolationException("Empty string for controller id not allowed",
+                    Collections.emptySet());
+        }
+
         if (targetRepository.findByControllerId(target.getControllerId()) != null) {
             throw new EntityAlreadyExistsException(target.getControllerId());
         }
diff --git a/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/ControllerManagementTest.java b/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/ControllerManagementTest.java
index 8289b8173..41a7c7848 100644
--- a/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/ControllerManagementTest.java
+++ b/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/ControllerManagementTest.java
@@ -9,10 +9,13 @@
 package org.eclipse.hawkbit.repository;
 
 import static org.fest.assertions.api.Assertions.assertThat;
+import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.validation.ConstraintViolationException;
+
 import org.apache.commons.lang3.RandomStringUtils;
 import org.eclipse.hawkbit.AbstractIntegrationTest;
 import org.eclipse.hawkbit.TestDataUtil;
@@ -71,6 +74,24 @@ public class ControllerManagementTest extends AbstractIntegrationTest {
                 .getNumberOfElements()).isEqualTo(3);
     }
 
+    @Test
+    @Description("Register a controller which not exist")
+    public void testfindOrRegisterTargetIfItDoesNotexist() {
+        final Target target = controllerManagament.findOrRegisterTargetIfItDoesNotexist("AA", null);
+        assertThat(target).as("target should not be null").isNotNull();
+
+        final Target sameTarget = controllerManagament.findOrRegisterTargetIfItDoesNotexist("AA", null);
+        assertThat(target).as("Target should be the equals").isEqualTo(sameTarget);
+        assertThat(targetRepository.count()).as("Only 1 target should be registred").isEqualTo(1L);
+
+        try {
+            controllerManagament.findOrRegisterTargetIfItDoesNotexist("", null);
+            fail("target with empty controller id should not be registred");
+        } catch (final ConstraintViolationException e) {
+            // ok
+        }
+    }
+
     @Test
     @Description("Controller trys to finish an update process after it has been finished by an error action status.")
     public void tryToFinishUpdateProcessMoreThenOnce() {
diff --git a/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/TargetManagementTest.java b/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/TargetManagementTest.java
index a7b8e673f..72f1951c6 100644
--- a/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/TargetManagementTest.java
+++ b/hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/TargetManagementTest.java
@@ -26,6 +26,7 @@ import java.util.Set;
 import java.util.stream.Collectors;
 
 import javax.persistence.Query;
+import javax.validation.ConstraintViolationException;
 
 import org.eclipse.hawkbit.AbstractIntegrationTest;
 import org.eclipse.hawkbit.TestDataUtil;
@@ -65,6 +66,17 @@ public class TargetManagementTest extends AbstractIntegrationTest {
         }
     }
 
+    @Test
+    @Description("Verify that a target with empty controller id cannot be created")
+    public void createTarget() {
+        try {
+            targetManagement.createTarget(new Target(""));
+            fail("target with empty controller id should not be created");
+        } catch (final ConstraintViolationException e) {
+            // ok
+        }
+    }
+
     @Test
     @Description("Ensures that targets can assigned and unassigned to a target tag. Not exists target will be ignored for the assignment.")
     public void assignAndUnassignTargetsToTag() {