diff --git a/afids_utils/tests/strategies.py b/afids_utils/tests/strategies.py
index 772c37a5..f8d929c5 100644
--- a/afids_utils/tests/strategies.py
+++ b/afids_utils/tests/strategies.py
@@ -8,7 +8,7 @@
 from hypothesis.extra.numpy import arrays
 from numpy.typing import NDArray
 
-from afids_utils.afids import AfidPosition, AfidSet
+from afids_utils.afids import AfidPosition, AfidSet, AfidVoxel
 
 
 @st.composite
@@ -105,8 +105,8 @@ def voxel_coords(
     draw: st.DrawFn,
     min_value: int = -50,
     max_value: int = 50,
-) -> AfidPosition:
-    return AfidPosition(
+) -> AfidVoxel:
+    return AfidVoxel(
         label=draw(st.integers(min_value=1, max_value=32)),
         i=draw(st.integers(min_value=min_value, max_value=max_value)),
         j=draw(st.integers(min_value=min_value, max_value=max_value)),
diff --git a/afids_utils/tests/test_transforms.py b/afids_utils/tests/test_transforms.py
index 0e7b9c3c..c45d0e76 100644
--- a/afids_utils/tests/test_transforms.py
+++ b/afids_utils/tests/test_transforms.py
@@ -4,21 +4,46 @@
 from hypothesis import HealthCheck, given, settings
 from numpy.typing import NDArray
 
-from afids_utils.tests.strategies import affine_xfm, world_coord
-from afids_utils.transforms import afid_world2voxel
+from afids_utils.afids import AfidPosition, AfidVoxel
+from afids_utils.tests.strategies import (
+    affine_xfms,
+    world_coords,
+    voxel_coords,
+)
+from afids_utils.transforms import world_to_voxel, voxel_to_world
 
 
 class TestAfidWorld2Voxel:
-    @given(world_coord=world_coord(), nii_affine=affine_xfm())
+    @given(world_coord=world_coords(), nii_affine=affine_xfms())
     @settings(
         deadline=400,
         suppress_health_check=[HealthCheck.function_scoped_fixture],
     )
-    def test_transform_output(
-        self, world_coord: NDArray[np.float_], nii_affine: NDArray[np.float_]
+    def test_world_to_voxel_xfm(
+        self, world_coord: AfidPosition, nii_affine: NDArray[np.float_]
     ):
-        voxel_coord = afid_world2voxel(world_coord, nii_affine)
+        voxel_coord = world_to_voxel(world_coord, nii_affine)
 
-        assert isinstance(voxel_coord, np.ndarray)
-        assert voxel_coord.dtype == np.int_
-        assert voxel_coord.shape == (3,)
+        assert isinstance(voxel_coord, AfidVoxel)
+        # Have to assert specific int dtype
+        assert isinstance(voxel_coord.i, np.int64)
+        assert isinstance(voxel_coord.j, np.int64)
+        assert isinstance(voxel_coord.k, np.int64)
+
+
+class TestAfidVoxel2World:
+    @given(voxel_coord=voxel_coords(), nii_affine=affine_xfms())
+    @settings(
+        deadline=400,
+        suppress_health_check=[HealthCheck.function_scoped_fixture],
+    )
+    def test_voxel_to_world_xfm(
+        self, voxel_coord: AfidVoxel, nii_affine: NDArray[np.float_]
+    ):
+        world_coord = voxel_to_world(voxel_coord, nii_affine)
+
+        assert isinstance(world_coord, AfidPosition)
+        # Have to assert specific float dtype
+        assert isinstance(world_coord.x, np.float64)
+        assert isinstance(world_coord.y, np.float64)
+        assert isinstance(world_coord.z, np.float64)
diff --git a/afids_utils/transforms.py b/afids_utils/transforms.py
index 28f0b94f..e0994b80 100644
--- a/afids_utils/transforms.py
+++ b/afids_utils/transforms.py
@@ -71,11 +71,12 @@ def voxel_to_world(
     """
 
     # Put into numpy array for easier computation
-    voxel_pos = np.asarray([afid_voxel.i, afid_voxel.j, afid_voxel.k, 1])
+    voxel_pos = np.asarray([afid_voxel.i, afid_voxel.j, afid_voxel.k])
 
     # Convert to float, perform rotation, translation
-    world_pos = np.dot(nii_affine[:3, :3], voxel_pos)
-    world_pos = world_pos + nii_affine[:3, 3:4]
+    world_pos = voxel_pos.astype(float)
+    world_pos = np.dot(nii_affine[:3, :3], world_pos)
+    world_pos = world_pos + nii_affine[:3, 3:4].T[0]
 
     return AfidPosition(
         label=afid_voxel.label,