diff --git a/io_scene_psk_psa/psa/importer.py b/io_scene_psk_psa/psa/importer.py
index 31a902c..c837e11 100644
--- a/io_scene_psk_psa/psa/importer.py
+++ b/io_scene_psk_psa/psa/importer.py
@@ -31,9 +31,9 @@ class ImportBone(object):
         self.parent: Optional[ImportBone] = None
         self.armature_bone = None
         self.pose_bone = None
-        self.orig_loc: Vector = Vector()
-        self.orig_quat: Quaternion = Quaternion()
-        self.post_quat: Quaternion = Quaternion()
+        self.original_location: Vector = Vector()
+        self.original_rotation: Quaternion = Quaternion()
+        self.post_rotation: Quaternion = Quaternion()
         self.fcurves: List[FCurve] = []
 
 
@@ -41,17 +41,17 @@ def _calculate_fcurve_data(import_bone: ImportBone, key_data: typing.Iterable[fl
     # Convert world-space transforms to local-space transforms.
     key_rotation = Quaternion(key_data[0:4])
     key_location = Vector(key_data[4:])
-    q = import_bone.post_quat.copy()
-    q.rotate(import_bone.orig_quat)
+    q = import_bone.post_rotation.copy()
+    q.rotate(import_bone.original_rotation)
     quat = q
-    q = import_bone.post_quat.copy()
+    q = import_bone.post_rotation.copy()
     if import_bone.parent is None:
         q.rotate(key_rotation.conjugated())
     else:
         q.rotate(key_rotation)
     quat.rotate(q.conjugated())
-    loc = key_location - import_bone.orig_loc
-    loc.rotate(import_bone.post_quat.conjugated())
+    loc = key_location - import_bone.original_location
+    loc.rotate(import_bone.post_rotation.conjugated())
     return quat.w, quat.x, quat.y, quat.z, loc.x, loc.y, loc.z
 
 
@@ -142,23 +142,16 @@ def import_psa(context: Context, psa_reader: PsaReader, armature_object: Object,
         if armature_bone.parent is not None and armature_bone.parent.name in psa_bone_names:
             import_bone.parent = import_bones_dict[armature_bone.parent.name]
         # Calculate the original location & rotation of each bone (in world-space maybe?)
-        if armature_bone.get('orig_quat') is not None:
-            # TODO: ideally we don't rely on bone auxiliary data like this, the non-aux data path is incorrect
-            # (animations are flipped 180 around Z)
-            import_bone.orig_quat = Quaternion(armature_bone['orig_quat'])
-            import_bone.orig_loc = Vector(armature_bone['orig_loc'])
-            import_bone.post_quat = Quaternion(armature_bone['post_quat'])
+        if import_bone.parent is not None:
+            import_bone.original_location = armature_bone.matrix_local.translation - armature_bone.parent.matrix_local.translation
+            import_bone.original_location.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
+            import_bone.original_rotation = armature_bone.matrix_local.to_quaternion()
+            import_bone.original_rotation.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
+            import_bone.original_rotation.conjugate()
         else:
-            if import_bone.parent is not None:
-                import_bone.orig_loc = armature_bone.matrix_local.translation - armature_bone.parent.matrix_local.translation
-                import_bone.orig_loc.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
-                import_bone.orig_quat = armature_bone.matrix_local.to_quaternion()
-                import_bone.orig_quat.rotate(armature_bone.parent.matrix_local.to_quaternion().conjugated())
-                import_bone.orig_quat.conjugate()
-            else:
-                import_bone.orig_loc = armature_bone.matrix_local.translation.copy()
-                import_bone.orig_quat = armature_bone.matrix_local.to_quaternion()
-            import_bone.post_quat = import_bone.orig_quat.conjugated()
+            import_bone.original_location = armature_bone.matrix_local.translation.copy()
+            import_bone.original_rotation = armature_bone.matrix_local.to_quaternion()
+        import_bone.post_rotation = import_bone.original_rotation.conjugated()
 
     context.window_manager.progress_begin(0, len(sequences))
 
diff --git a/io_scene_psk_psa/psk/importer.py b/io_scene_psk_psa/psk/importer.py
index 0696edd..809fbad 100644
--- a/io_scene_psk_psa/psk/importer.py
+++ b/io_scene_psk_psa/psk/importer.py
@@ -39,9 +39,9 @@ class ImportBone:
         self.world_rotation_matrix: Matrix = Matrix()
         self.world_matrix: Matrix = Matrix()
         self.vertex_group = None
-        self.orig_quat: Quaternion = Quaternion()
-        self.orig_loc: Vector = Vector()
-        self.post_quat: Quaternion = Quaternion()
+        self.original_rotation: Quaternion = Quaternion()
+        self.original_location: Vector = Vector()
+        self.post_rotation: Quaternion = Quaternion()
 
 
 class PskImportResult:
@@ -111,12 +111,6 @@ def import_psk(psk: Psk, context, options: PskImportOptions) -> PskImportResult:
             edit_bone_matrix.translation = import_bone.world_matrix.translation
             edit_bone.matrix = edit_bone_matrix
 
-            # Store bind pose information in the bone's custom properties.
-            # This information is used when importing animations from PSA files.
-            edit_bone['orig_quat'] = import_bone.local_rotation
-            edit_bone['orig_loc'] = import_bone.local_translation
-            edit_bone['post_quat'] = import_bone.local_rotation.conjugated()
-
     # MESH
     if options.should_import_mesh:
         mesh_data = bpy.data.meshes.new(options.name)