diff --git a/examples/fluidity/advection2d/advection2d.py b/examples/fluidity/advection2d/advection2d.py
index a6bf5094..a66635e1 100644
--- a/examples/fluidity/advection2d/advection2d.py
+++ b/examples/fluidity/advection2d/advection2d.py
@@ -51,7 +51,7 @@ def _interp_vel_grad(int_time):
 @nb.njit(fastmath=True)
 def velocity(coords, time):
     """Return prescribed velocity for 2D simple shear flow."""
-    return np.array([coords[0] * STRAIN_RATE, 0.0])
+    return np.array([coords[1] * STRAIN_RATE, 0.0])
 
 
 @nb.njit(fastmath=True)