diff --git a/src/main/java/org/gcube/common/storagehub/model/items/FolderItem.java b/src/main/java/org/gcube/common/storagehub/model/items/FolderItem.java
index 8238e2f..98dabd4 100644
--- a/src/main/java/org/gcube/common/storagehub/model/items/FolderItem.java
+++ b/src/main/java/org/gcube/common/storagehub/model/items/FolderItem.java
@@ -19,5 +19,5 @@ public class FolderItem extends Item {
 
 	@NodeAttribute(value= PAYLOADBACKEND)
 	PayloadBackend backend = new PayloadBackend(Constants.DEFAULT_MINIO_STORAGE, null);
-	
+		
 }
diff --git a/src/main/java/org/gcube/common/storagehub/model/items/nodes/PayloadBackend.java b/src/main/java/org/gcube/common/storagehub/model/items/nodes/PayloadBackend.java
index b45f1f6..25c557e 100644
--- a/src/main/java/org/gcube/common/storagehub/model/items/nodes/PayloadBackend.java
+++ b/src/main/java/org/gcube/common/storagehub/model/items/nodes/PayloadBackend.java
@@ -13,7 +13,6 @@ import org.gcube.common.storagehub.model.annotations.AttributeRootNode;
 import org.gcube.common.storagehub.model.annotations.NodeAttribute;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
diff --git a/src/main/java/org/gcube/common/storagehub/model/plugins/PluginParameters.java b/src/main/java/org/gcube/common/storagehub/model/plugins/PluginParameters.java
index 5aedfd9..fd0a6e5 100644
--- a/src/main/java/org/gcube/common/storagehub/model/plugins/PluginParameters.java
+++ b/src/main/java/org/gcube/common/storagehub/model/plugins/PluginParameters.java
@@ -4,5 +4,5 @@ import java.util.Map;
 
 public interface PluginParameters {
 
-	Map<String, String> getParameters();
+	Map<String, Object> getParameters();
 }