diff --git a/resolve/extra.py b/resolve/extra.py
index c707879dde6d8d6132cb7848a30e694375e66518..6d8e85acc8431fb762360d6a7cd19c657fb5fbb7 100644
--- a/resolve/extra.py
+++ b/resolve/extra.py
@@ -5,7 +5,7 @@
 import nifty8 as ift
 
 from .mpi import master
-from data.observation import Observation
+from .data.observation import Observation
 
 
 def split_data_file(data_path, n_task, target_folder, base_name, n_work, compress):