diff --git a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsProducer.java b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsProducer.java
index 7def141..c9117b2 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsProducer.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsProducer.java
@@ -6,7 +6,8 @@ package org.gcube.portlets.widgets.workspacesharingwidget.server.notifications;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.gcube.application.framework.core.session.ASLSession;
 import org.gcube.application.framework.core.session.SessionManager;
 import org.gcube.applicationsupportlayer.social.NotificationsManager;
@@ -29,7 +30,7 @@ public class NotificationsProducer {
 
 	protected ScopeBean scope;
 	
-	protected static Logger logger = Logger.getLogger(NotificationsProducer.class);
+	protected static Logger logger = LoggerFactory.getLogger(NotificationsProducer.class);
 	
 	protected NotificationsManager notificationsMng;
 	protected ASLSession aslSession;
diff --git a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsUtil.java b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsUtil.java
index efac889..398c68d 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsUtil.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/notifications/NotificationsUtil.java
@@ -8,7 +8,8 @@ import java.util.List;
 
 import javax.servlet.http.HttpSession;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.gcube.common.homelibrary.home.workspace.Workspace;
 import org.gcube.common.homelibrary.home.workspace.WorkspaceFolder;
 import org.gcube.common.homelibrary.home.workspace.WorkspaceItem;
@@ -26,7 +27,7 @@ import org.gcube.portlets.widgets.workspacesharingwidget.shared.InfoContactModel
 public class NotificationsUtil {
 	
 	
-	protected static Logger logger = Logger.getLogger(NotificationsUtil.class);
+	protected static Logger logger = LoggerFactory.getLogger(NotificationsUtil.class);
 	
 	/**
 	 * Send a notification if an item is added or updated to sharing folder
diff --git a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/ScopeUtilFilter.java b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/ScopeUtilFilter.java
index 9ca5f3a..c672e5d 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/ScopeUtilFilter.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/ScopeUtilFilter.java
@@ -6,14 +6,15 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 
 public class ScopeUtilFilter {
 	
 	private static final String SCOPE_SEPARATOR = "/";
 	private String scopeRoot = null;
-	public static Logger logger = Logger.getLogger(ScopeUtilFilter.class);
+	public static Logger logger = LoggerFactory.getLogger(ScopeUtilFilter.class);
 	public Map<String, String> hashScopesFiltered = new HashMap<String, String>();
 	
 	public static final String ALLSCOPE = "All spaces";
diff --git a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/UserUtil.java b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/UserUtil.java
index 5d0a8f9..ef10705 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/UserUtil.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/UserUtil.java
@@ -3,7 +3,8 @@ package org.gcube.portlets.widgets.workspacesharingwidget.server.util;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.gcube.portlets.widgets.workspacesharingwidget.shared.InfoContactModel;
 import org.gcube.vomanagement.usermanagement.UserManager;
 import org.gcube.vomanagement.usermanagement.exception.UserManagementPortalException;
@@ -17,7 +18,7 @@ import org.gcube.vomanagement.usermanagement.model.UserModel;
 public class UserUtil {
 	
 	static UserManager um = new LiferayUserManager();
-	protected static Logger logger = Logger.getLogger(UserUtil.class);
+	protected static Logger logger = LoggerFactory.getLogger(UserUtil.class);
 
 	
 	/**
diff --git a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/WsUtil.java b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/WsUtil.java
index b53533d..0e0cc5a 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/WsUtil.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspacesharingwidget/server/util/WsUtil.java
@@ -6,7 +6,8 @@ package org.gcube.portlets.widgets.workspacesharingwidget.server.util;
 import javax.servlet.http.HttpSession;
 
 import org.apache.commons.lang.StringUtils;
-import org.apache.log4j.Logger;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.gcube.application.framework.core.session.ASLSession;
 import org.gcube.application.framework.core.session.SessionManager;
 import org.gcube.applicationsupportlayer.social.ApplicationNotificationsManager;
@@ -53,7 +54,7 @@ public class WsUtil {
 	public static final String TEST_USER_FULL_NAME = "Test User";
 	
 	
-	protected static Logger logger = Logger.getLogger(WsUtil.class);
+	protected static Logger logger = LoggerFactory.getLogger(WsUtil.class);
 
 	public static boolean withoutPortal = false;