diff --git a/_includes/filter_morphological/filter_morphological_act1_skimage_napari.py b/_includes/filter_morphological/filter_morphological_act1_skimage_napari.py
index 780bf707..7e14fabd 100644
--- a/_includes/filter_morphological/filter_morphological_act1_skimage_napari.py
+++ b/_includes/filter_morphological/filter_morphological_act1_skimage_napari.py
@@ -7,6 +7,7 @@
 from napari.viewer import Viewer
 from skimage.morphology import square, disk
 from skimage.morphology import erosion, dilation
+import numpy as np
 
 # %%
 # Create a napari_viewer