diff --git a/src/cyxtrax/io/save_map.py b/src/cyxtrax/io/save_map.py
index 00d685cca9eb3881f9557321691424c4a92733f9..086b667d2664e75fd234bd6c08d1513ee18b8146 100644
--- a/src/cyxtrax/io/save_map.py
+++ b/src/cyxtrax/io/save_map.py
@@ -40,8 +40,8 @@ def save_atlas(
 
     projection_points = file.require_dataset(
         "positions",
-        shape=(3, number_of_maps**3),  # Initial shape with third dimension as 0
-        maxshape=(3, number_of_maps**3),
+        shape=(3, number_of_maps),  # Initial shape with third dimension as 0
+        maxshape=(3, number_of_maps),
         dtype=np.float32,
     )
     if isinstance(mesh_list, dict):