diff --git a/src/topotoolbox/grid_object.py b/src/topotoolbox/grid_object.py
index 1a240ad..c1f1ada 100755
--- a/src/topotoolbox/grid_object.py
+++ b/src/topotoolbox/grid_object.py
@@ -64,6 +64,18 @@ def columns(self):
         """
         return self.z.shape[1]
 
+    @property
+    def dims(self):
+        """The dimensions of the grid in the correct order for libtopotoolbox
+        """
+        if self.z.flags.c_contiguous:
+            return (self.columns, self.rows)
+
+        if self.z.flags.f_contiguous:
+            return (self.rows, self.columns)
+
+        raise TypeError("Grid is not stored as a contiguous row- or column-major array")
+
     def reproject(self,
                   crs: 'CRS',
                   resolution: 'float | None' = None,
@@ -137,7 +149,7 @@ def fillsinks(self,
 
         """
 
-        dem = self.z.astype(np.float32, order='F')
+        dem = self.z.astype(np.float32)
         output = np.zeros_like(dem)
 
         restore_nans = False
@@ -161,9 +173,9 @@ def fillsinks(self,
 
         if hybrid:
             queue = np.zeros_like(dem, dtype=np.int64)
-            _grid.fillsinks_hybrid(output, queue, dem, bc, self.shape)
+            _grid.fillsinks_hybrid(output, queue, dem, bc, self.dims)
         else:
-            _grid.fillsinks(output, dem, bc, self.shape)
+            _grid.fillsinks(output, dem, bc, self.dims)
 
         if restore_nans:
             dem[nans] = np.nan
diff --git a/tests/test_grid_object.py b/tests/test_grid_object.py
index 8da6ef6..73052e7 100755
--- a/tests/test_grid_object.py
+++ b/tests/test_grid_object.py
@@ -3,6 +3,8 @@
 
 import topotoolbox as topo
 
+import opensimplex
+
 
 @pytest.fixture
 def square_dem():
@@ -67,6 +69,40 @@ def test_fillsinks(square_dem, wide_dem, tall_dem):
                 assert sink < 8
 
 
+def test_fillsinks_order():
+    opensimplex.seed(12)
+
+    x = np.arange(0,128)
+    y = np.arange(0,256)
+
+    dem_C = topo.GridObject()
+    dem_C.z = 64 * (opensimplex.noise2array(x,y) + 1)
+
+    assert dem_C.shape[0] == 256
+    assert dem_C.shape[1] == 128
+    
+    assert dem_C.z.flags.c_contiguous
+    assert dem_C.dims[0] == 128
+    assert dem_C.dims[1] == 256
+    
+    dem_F = topo.GridObject()
+    dem_F.z = np.asfortranarray(dem_C.z)
+
+    assert dem_F.shape[0] == 256
+    assert dem_F.shape[1] == 128
+    
+    assert dem_F.z.flags.f_contiguous
+    assert dem_F.dims[0] == 256
+    assert dem_F.dims[1] == 128
+
+    filled_C = dem_C.fillsinks()
+    assert filled_C.z.flags.c_contiguous
+    
+    filled_F = dem_F.fillsinks()    
+    assert filled_F.z.flags.f_contiguous
+   
+    assert np.array_equal(filled_F.z, filled_C.z)
+    
 def test_identifyflats(square_dem, wide_dem, tall_dem):
     # TODO: add more tests
     for dem in [square_dem, wide_dem, tall_dem]: