diff --git a/content/index.rst b/content/index.rst
index f9d5fec1d6b123c6bc7469f347ac37d3d991515f..fb6cc98a1a4c83ed32843d85eba3a712b5797466 100644
--- a/content/index.rst
+++ b/content/index.rst
@@ -50,8 +50,8 @@ The complete code that constructs the graphene flake shown on the right side is
 .. code:: python
 
           def disk(pos):
-          x, y = pos
-          return x**2 + y**2 < 8**2
+              x, y = pos
+              return x**2 + y**2 < 8**2
 
           lat = kwant.lattice.honeycomb()
           sys = kwant.Builder()