diff --git a/eis_toolkit/vector_processing/idw_interpolation.py b/eis_toolkit/vector_processing/idw_interpolation.py
index afcaced0..5432926b 100644
--- a/eis_toolkit/vector_processing/idw_interpolation.py
+++ b/eis_toolkit/vector_processing/idw_interpolation.py
@@ -67,7 +67,7 @@ def _idw_core(x, y, z, xi, yi: np.ndarray, power: Number, search_radius: Optiona
             over += z[n] / dist
             under += 1.0 / dist
 
-    interpolated_values = over / under
+    interpolated_values = np.divide(over, under, out=np.full_like(over, np.nan), where=under != 0)
     return interpolated_values