diff --git a/doc/python/3d-mesh.md b/doc/python/3d-mesh.md
index a0d4f621471..4c846920953 100644
--- a/doc/python/3d-mesh.md
+++ b/doc/python/3d-mesh.md
@@ -103,6 +103,8 @@ fig.show()
 
 ```python
 import plotly.graph_objects as go
+import numpy as np
+
 fig = go.Figure(data=[
     go.Mesh3d(
         # 8 vertices of a cube