diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index ce0891e7cb497e6bd62e6de3d1ae0218ecd41039..3dbcf702757729e347556b7cb8d48ea734e1e5cb 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -149,8 +149,9 @@ class Files:
             fname = self.flist[self._current_index]
             t_start = self.ftimes[self._current_index, 0]
             t_stop = self.ftimes[self._current_index, 1]
+            dto = self.dto_s[self._current_index]
             self._current_index += 1
-            return fname, t_start, t_stop
+            return fname, t_start, t_stop, dto
 
         self._current_index = 0
         raise StopIteration