diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index 17b82d79418f401ebf2da6cd36d48383dcfff32b..7be569e9cbadd39df59fe2ac4579e6266909a095 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -108,6 +108,10 @@ class Files:
         self.dto_s = self.dto_s[sidxs]
 
         self._current_index = 0
+        self.number_of_files = len(self.flist)
+
+    def get_number_of_files(self):
+        return self.number_of_files
 
     def get_datetime(self, pathname):
         """