diff --git a/xcompact3d_toolbox/io.py b/xcompact3d_toolbox/io.py
index 0472015..1b9451d 100644
--- a/xcompact3d_toolbox/io.py
+++ b/xcompact3d_toolbox/io.py
@@ -716,7 +716,9 @@ def is_velocity(name):
                 dataset["phi"] = (
                     stack_variables(scalar_variables, stack_scalar=False)
                     .to_array(dim="n")
-                    .assign_coords(n=[int(var[-1]) for var in scalar_variables])
+                    .assign_coords(
+                        n=[int(v[-self.filename_properties.scalar_num_of_digits :]) for v in scalar_variables]
+                    )
                 )
                 set_of_variables -= set(scalar_variables)