diff --git a/src/genomic_features/ensembl/ensembldb.py b/src/genomic_features/ensembl/ensembldb.py
index 82f420d..2e34287 100644
--- a/src/genomic_features/ensembl/ensembldb.py
+++ b/src/genomic_features/ensembl/ensembldb.py
@@ -309,7 +309,13 @@ def _build_query(
         else:
             query = self.db.table(table)
         # add filter
-        query = query.filter(filter.convert()).select(cols).order_by(cols)
+
+        filter = filter.convert()
+        if filter is None:
+            query = query.select(cols).order_by(cols)
+        else:
+            query = query.filter(filter).select(cols).order_by(cols)
+
         return query
 
     def _join_query(