diff --git a/hawkbit-dmf/hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpMessageHandlerService.java b/hawkbit-dmf/hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpMessageHandlerService.java
index 6b2dc67f1..7ec9bb943 100644
--- a/hawkbit-dmf/hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpMessageHandlerService.java
+++ b/hawkbit-dmf/hawkbit-dmf-amqp/src/main/java/org/eclipse/hawkbit/amqp/AmqpMessageHandlerService.java
@@ -13,6 +13,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.UUID;
 import java.util.stream.Collectors;
@@ -42,6 +43,7 @@ import org.springframework.amqp.AmqpRejectAndDontRequeueException;
 import org.springframework.amqp.core.Message;
 import org.springframework.amqp.rabbit.annotation.RabbitListener;
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.messaging.converter.MessageConversionException;
 import org.springframework.messaging.handler.annotation.Header;
 import org.springframework.security.authentication.AnonymousAuthenticationToken;
 import org.springframework.security.core.Authentication;