diff --git a/src/main/java/org/gcube/portal/databook/server/DBCassandraAstyanaxImpl.java b/src/main/java/org/gcube/portal/databook/server/DBCassandraAstyanaxImpl.java
index 8b6b1b8..fb78f92 100644
--- a/src/main/java/org/gcube/portal/databook/server/DBCassandraAstyanaxImpl.java
+++ b/src/main/java/org/gcube/portal/databook/server/DBCassandraAstyanaxImpl.java
@@ -1495,7 +1495,8 @@ public final class DBCassandraAstyanaxImpl implements DatabookStore {
 		for (Row<String, String> row : result.getResult()) {
 			for (Column<String> column : row.getColumns()) {
 				int curValue = Integer.parseInt(column.getStringValue());
-				toReturn.put(column.getName(), curValue);
+				if (curValue > 0)
+					toReturn.put(column.getName(), curValue);
 			}
 		}
 		return toReturn;