diff --git a/doc/interpolation.rst b/doc/interpolation.rst
index 63e9a7cd35e..22a01255df5 100644
--- a/doc/interpolation.rst
+++ b/doc/interpolation.rst
@@ -151,7 +151,7 @@ Additional keyword arguments can be passed to scipy's functions.
     # fill 0 for the outside of the original coordinates.
     da.interp(x=np.linspace(-0.5, 1.5, 10), kwargs={'fill_value': 0.0})
     # extrapolation
-    da.interp(x=np.linspace(-0.5, 1.5, 10), kwargs={'fill_value': 'extrapolate'})
+    da.interp(x=np.linspace(-0.5, 1.5, 10), kwargs={'fill_value': None})
 
 
 Advanced Interpolation