diff --git a/meteor/rsmap.py b/meteor/rsmap.py
index fb0e1a9..f5811cc 100644
--- a/meteor/rsmap.py
+++ b/meteor/rsmap.py
@@ -8,9 +8,12 @@
 import numpy as np
 import pandas as pd
 import reciprocalspaceship as rs
+from reciprocalspaceship.decorators import cellify, spacegroupify
 
 from .settings import GEMMI_HIGH_RESOLUTION_BUFFER
 from .utils import (
+    CellType,
+    SpacegroupType,
     canonicalize_amplitudes,
     complex_array_to_rs_dataseries,
     numpy_array_to_map,
@@ -63,6 +66,8 @@ class Map(rs.DataSet):
     # in addition, __init__ specifies 3 columns special that can be named dynamically to support:
     # amplitudes, phases, uncertainties; all other columns are forbidden
 
+    @cellify
+    @spacegroupify
     def __init__(
         self,
         data: dict | pd.DataFrame | rs.DataSet,
@@ -208,6 +213,9 @@ def get_hkls(self) -> np.ndarray:
     def compute_dHKL(self) -> rs.DataSeries:  # noqa: N802, caps from reciprocalspaceship
         # rs adds a "dHKL" column to the DataFrame
         # that could be enabled by adding "dHKL" to _allowed_columns - @tjlane
+        if not hasattr(self, "cell"):
+            msg = "no `cell` attribute set, cannot compute resolution (d-values)"
+            raise AttributeError(msg)
         d_hkl = self.cell.calculate_d_array(self.get_hkls())
         return rs.DataSeries(d_hkl, dtype="R", index=self.index)
 
@@ -288,13 +296,15 @@ def to_structurefactor(self) -> rs.DataSeries:
         return super().to_structurefactor(self._amplitude_column, self._phase_column)
 
     @classmethod
+    @cellify("cell")
+    @spacegroupify("spacegroup")
     def from_structurefactor(
         cls,
         complex_structurefactor: np.ndarray | rs.DataSeries,
         *,
         index: pd.Index,
-        cell: Any = None,
-        spacegroup: Any = None,
+        cell: CellType | None = None,
+        spacegroup: SpacegroupType | None = None,
     ) -> Map:
         # 1. `rs.DataSet.from_structurefactor` exists, but it operates on a column that's already
         #    part of the dataset; having such a (redundant) column is forbidden by `Map`
@@ -326,8 +336,9 @@ def from_gemmi(
         )
 
     @classmethod
+    @cellify("cell")
     def from_3d_numpy_map(
-        cls, map_grid: np.ndarray, *, spacegroup: Any, cell: Any, high_resolution_limit: float
+        cls, map_grid: np.ndarray, *, spacegroup: Any, cell: CellType, high_resolution_limit: float
     ) -> Map:
         """
         Create a `Map` from a 3d grid of voxel values stored in a numpy array.
diff --git a/meteor/utils.py b/meteor/utils.py
index 2036f0d..2c1d2fc 100644
--- a/meteor/utils.py
+++ b/meteor/utils.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from collections.abc import Sequence
 from typing import Literal, overload
 
 import gemmi
@@ -7,8 +8,12 @@
 import reciprocalspaceship as rs
 from pandas import Index
 from reciprocalspaceship import DataSet
+from reciprocalspaceship.decorators import cellify, spacegroupify
 from reciprocalspaceship.utils import canonicalize_phases
 
+CellType = Sequence[float] | np.ndarray | gemmi.UnitCell
+SpacegroupType = str | int | gemmi.SpaceGroup
+
 
 class ShapeMismatchError(Exception): ...
 
@@ -147,11 +152,13 @@ def complex_array_to_rs_dataseries(
     return amplitudes, phases
 
 
+@cellify("cell")
+@spacegroupify("spacegroup")
 def numpy_array_to_map(
     array: np.ndarray,
     *,
-    spacegroup: str | int | gemmi.SpaceGroup,
-    cell: tuple[float, float, float, float, float, float] | gemmi.UnitCell,
+    spacegroup: SpacegroupType,
+    cell: CellType,
 ) -> gemmi.Ccp4Map:
     ccp4_map = gemmi.Ccp4Map()
     ccp4_map.grid = gemmi.FloatGrid(array.astype(np.float32))
diff --git a/test/unit/test_rsmap.py b/test/unit/test_rsmap.py
index 67903cf..2394927 100644
--- a/test/unit/test_rsmap.py
+++ b/test/unit/test_rsmap.py
@@ -195,6 +195,10 @@ def test_compute_dhkl(noise_free_map: Map) -> None:
     assert np.min(d_hkl) == 1.0
     assert d_hkl.shape == noise_free_map.amplitudes.shape
 
+    noise_free_map.cell = None
+    with pytest.raises(AttributeError):
+        _ = noise_free_map.compute_dHKL()
+
 
 def test_resolution_limits(random_difference_map: Map) -> None:
     dmax, dmin = random_difference_map.resolution_limits