diff --git a/docs/source/tutorial/graphene_example.md b/docs/source/tutorial/graphene_example.md
index afda9f26739a0bd8d842f23032c871d9893b37de..da47de2f515dbec0f68b511f32f6f04c9e28f0cf 100644
--- a/docs/source/tutorial/graphene_example.md
+++ b/docs/source/tutorial/graphene_example.md
@@ -75,7 +75,7 @@ def onsite_int(site, U):
     return U * sx
 
 def nn_int(site1, site2, V):
-    return V * sx
+    return V * np.ones((2, 2))
 
 builder_int = utils.build_interacting_syst(
     builder=bulk_graphene,