diff --git a/core/src/main/java/ch/dissem/bitmessage/ports/AbstractMessageRepository.java b/core/src/main/java/ch/dissem/bitmessage/ports/AbstractMessageRepository.java
index e037c4f..e0448c7 100644
--- a/core/src/main/java/ch/dissem/bitmessage/ports/AbstractMessageRepository.java
+++ b/core/src/main/java/ch/dissem/bitmessage/ports/AbstractMessageRepository.java
@@ -70,7 +70,11 @@ public abstract class AbstractMessageRepository implements MessageRepository, In
 
     @Override
     public List<Plaintext> findMessages(Label label) {
-        return find("id IN (SELECT message_id FROM Message_Label WHERE label_id=" + label.getId() + ")");
+        if (label == null) {
+            return find("id NOT IN (SELECT message_id FROM Message_Label)");
+        } else {
+            return find("id IN (SELECT message_id FROM Message_Label WHERE label_id=" + label.getId() + ")");
+        }
     }
 
     @Override
diff --git a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcProofOfWorkRepository.java b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcProofOfWorkRepository.java
index ac6e69f..0fda3fa 100644
--- a/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcProofOfWorkRepository.java
+++ b/repositories/src/main/java/ch/dissem/bitmessage/repository/JdbcProofOfWorkRepository.java
@@ -2,7 +2,6 @@ package ch.dissem.bitmessage.repository;
 
 import ch.dissem.bitmessage.InternalContext;
 import ch.dissem.bitmessage.entity.ObjectMessage;
-import ch.dissem.bitmessage.entity.Plaintext;
 import ch.dissem.bitmessage.exception.ApplicationException;
 import ch.dissem.bitmessage.factory.Factory;
 import ch.dissem.bitmessage.ports.ProofOfWorkRepository;
@@ -10,9 +9,7 @@ import ch.dissem.bitmessage.utils.Strings;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.sql.*;
 import java.util.LinkedList;
 import java.util.List;