diff --git a/movement/utils/vector.py b/movement/utils/vector.py
index ca7430df1..ec6d92758 100644
--- a/movement/utils/vector.py
+++ b/movement/utils/vector.py
@@ -82,7 +82,10 @@ def convert_to_unit(data: xr.DataArray) -> xr.DataArray:
     """
     if "space" in data.dims:
         validate_dims_coords(data, {"space": ["x", "y"]})
-        return data / compute_norm(data)
+        norm = compute_norm(data)
+        unit = data / norm
+        unit = xr.where(norm == 0, np.nan, unit)
+        return unit
     elif "space_pol" in data.dims:
         validate_dims_coords(data, {"space_pol": ["rho", "phi"]})
         # Set both rho and phi values to NaN at null vectors (where rho = 0)
@@ -144,8 +147,7 @@ def cart2pol(data: xr.DataArray) -> xr.DataArray:
     # Make all zeros in phi positive zeros
     # - where rho == 0, set phi to 0
     # - where rho != 0, keep the phi value from atan2
-    phi = xr.where(np.isclose(rho.values, 0.0, atol=1e-9), 0.0, phi)
-
+    phi = xr.where(np.isclose(rho, 0.0, atol=1e-9), 0.0, phi)
     # Replace space dim with space_pol
     dims = list(data.dims)
     dims[dims.index("space")] = "space_pol"
@@ -298,11 +300,12 @@ def compute_signed_angle_2d(
         cross *= -1.0
     dot = u_x * v_x + u_y * v_y
 
-    angles = np.arctan2(cross, dot)
-    assert isinstance(angles, xr.DataArray)
+    angles = xr.apply_ufunc(np.arctan2, cross, dot)
+
     # arctan2 returns values in [-pi, pi].
-    # We need to map -pi angles to pi, to stay in the (-pi, pi] range
-    angles.values[angles <= -np.pi] = np.pi
+    # Map -pi to pi to stay in the (-pi, pi] range
+    angles = xr.where(angles <= -np.pi, np.pi, angles)
+
     angles.name = "signed_angle"
     return angles
 
diff --git a/pyproject.toml b/pyproject.toml
index c8cb184bd..3ce349f28 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@ dependencies = [
   "numpy>=2.0.0",
   "pandas",
   "h5py",
-  "netCDF4<1.7.3",
+  "netCDF4>=1.7.2,<1.7.3",
   "tables>=3.10.1",
   "attrs",
   "pooch",