diff --git a/dev-environment.yml b/dev-environment.yml
index 1759f338..706f11d1 100644
--- a/dev-environment.yml
+++ b/dev-environment.yml
@@ -15,7 +15,7 @@ dependencies:
   - tqdm
   - scikit-image
   - scikit-gstat>=1.0
-#  - geoutils=0.0.14
+  - geoutils=0.0.15
 
   # Development-specific, to mirror manually in setup.cfg [options.extras_require].
   - pip
@@ -52,4 +52,4 @@ dependencies:
     - noisyopt
 
     # To run CI against latest GeoUtils
-    - git+https://github.com/GlacioHack/geoutils.git
+#    - git+https://github.com/GlacioHack/geoutils.git
diff --git a/environment.yml b/environment.yml
index 82d4e6ae..09090f46 100644
--- a/environment.yml
+++ b/environment.yml
@@ -15,8 +15,8 @@ dependencies:
   - tqdm
   - scikit-image
   - scikit-gstat>=1.0
-#  - geoutils=0.0.14
+  - geoutils=0.0.15
   - pip
 
   - pip:
-     - git+https://github.com/GlacioHack/geoutils.git
+#     - git+https://github.com/GlacioHack/geoutils.git
diff --git a/tests/test_coreg/test_affine.py b/tests/test_coreg/test_affine.py
index 3c553b02..49f45a68 100644
--- a/tests/test_coreg/test_affine.py
+++ b/tests/test_coreg/test_affine.py
@@ -286,7 +286,7 @@ def test_tilt(self) -> None:
         assert np.abs(np.mean(periglacial_offset)) < np.abs(np.mean(pre_offset))
 
         # Check that the mean periglacial offset is low
-        assert np.abs(np.mean(periglacial_offset)) < 2
+        assert np.abs(np.mean(periglacial_offset)) < 0.01
 
     def test_icp_opencv(self) -> None:
         warnings.simplefilter("error")
diff --git a/xdem/coreg/affine.py b/xdem/coreg/affine.py
index 2f263cec..4462a971 100644
--- a/xdem/coreg/affine.py
+++ b/xdem/coreg/affine.py
@@ -621,6 +621,7 @@ def _fit_func(
     ) -> None:
         """Fit the dDEM between the DEMs to a least squares polynomial equation."""
         ddem = ref_dem - tba_dem
+        ddem[~inlier_mask] = np.nan
         x_coords, y_coords = _get_x_and_y_coords(ref_dem.shape, transform)
         fit_ramp, coefs = deramping(
             ddem, x_coords, y_coords, degree=self.poly_order, subsample=self._meta["subsample"], verbose=verbose