diff --git a/pyresample/geometry.py b/pyresample/geometry.py
index 0dfa633d7..6e3de3179 100644
--- a/pyresample/geometry.py
+++ b/pyresample/geometry.py
@@ -2595,8 +2595,8 @@ def get_area_slices(self, area_to_cover, shape_divisible_by=None):
             y_slice = _ensure_integer_slice(y_slice)
             return x_slice, y_slice
 
-        data_boundary = self._get_area_to_cover_boundary(self)
-        area_boundary = self._get_area_to_cover_boundary(area_to_cover)
+        data_boundary = _get_area_boundary(self)
+        area_boundary = _get_area_boundary(area_to_cover)
         intersection = data_boundary.contour_poly.intersection(
             area_boundary.contour_poly)
         if intersection is None:
@@ -2618,16 +2618,6 @@ def get_area_slices(self, area_to_cover, shape_divisible_by=None):
         return (check_slice_orientation(x_slice),
                 check_slice_orientation(y_slice))
 
-    @staticmethod
-    def _get_area_to_cover_boundary(area_to_cover: AreaDefinition) -> Boundary:
-        try:
-            if area_to_cover.is_geostationary:
-                return Boundary(*get_geostationary_bounding_box_in_lonlats(area_to_cover))
-            boundary_shape = max(max(*area_to_cover.shape) // 100 + 1, 3)
-            return area_to_cover.boundary(frequency=boundary_shape, force_clockwise=True)
-        except ValueError:
-            raise NotImplementedError("Can't determine boundary of area to cover")
-
     def crop_around(self, other_area):
         """Crop this area around `other_area`."""
         xslice, yslice = self.get_area_slices(other_area)
@@ -2727,6 +2717,16 @@ def geocentric_resolution(self, ellps='WGS84', radius=None):
         return res
 
 
+def _get_area_boundary(area_to_cover: AreaDefinition) -> Boundary:
+    try:
+        if area_to_cover.is_geostationary:
+            return Boundary(*get_geostationary_bounding_box_in_lonlats(area_to_cover))
+        boundary_shape = max(max(*area_to_cover.shape) // 100 + 1, 3)
+        return area_to_cover.boundary(frequency=boundary_shape, force_clockwise=True)
+    except ValueError:
+        raise NotImplementedError("Can't determine boundary of area to cover")
+
+
 def _make_slice_divisible(sli, max_size, factor=2):
     """Make the given slice even in size."""
     rem = (sli.stop - sli.start) % factor