diff --git a/CHANGES.rst b/CHANGES.rst
index 30de3b8c8..c1ed02867 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,6 +2,14 @@
 Changelog
 =========
 
+v0.47.0 (unreleased)
+--------------------
+Contributors to this version: Juliette Lavoie (:user:`juliettelavoie`)
+
+Bug fixes
+^^^^^^^^^
+* Fixed a bug with ``n_escore=-1`` in ``xclim.sdba.adjustment.NpdfTransform`` (:issue:`1515`, :pull:`1515`).
+
 v0.46.0 (2023-10-24)
 --------------------
 Contributors to this version: David Huard (:user:`huard`), Trevor James Smith (:user:`Zeitsperre`), Pascal Bourgault (:user:`aulemahal`), Éric Dupuis (:user:`coxipi`).
diff --git a/xclim/sdba/_adjustment.py b/xclim/sdba/_adjustment.py
index a28f9c03a..5a651a7ea 100644
--- a/xclim/sdba/_adjustment.py
+++ b/xclim/sdba/_adjustment.py
@@ -309,7 +309,7 @@ def npdf_transform(ds: xr.Dataset, **kwargs) -> xr.Dataset:
         # All NaN, but with the proper shape.
         escores = (
             ref.isel({dim: 0, "time": 0}) * hist.isel({dim: 0, "time": 0})
-        ).expand_dims(iterations=ds.iteration) * np.NaN
+        ).expand_dims(iterations=ds.iterations) * np.NaN
 
     return xr.Dataset(
         data_vars={