diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index 702c8ad3086664a22e9cab8b1e30a5c339337c4f..4f51c2d4182a4b784273d54012fdfccc7a4358db 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -142,7 +142,7 @@ class AMVFiles:
 
     def get_file_containing_time(self, timestamp):
         k = -1
-        for i in range(len(self.ftimes.shape[0])):
+        for i in range(self.ftimes.shape[0]):
             if (timestamp >= self.ftimes[i, 0]) and (timestamp < self.ftimes[i, 1]):
                 k = i
                 break