diff --git a/pub/python/vol1/ft03_heat.py b/pub/python/vol1/ft03_heat.py
index 66705c71..fab7383b 100644
--- a/pub/python/vol1/ft03_heat.py
+++ b/pub/python/vol1/ft03_heat.py
@@ -11,8 +11,11 @@
 """
 
 from __future__ import print_function
-from fenics import *
+
+# Hold plot
+import matplotlib.pyplot as plt
 import numpy as np
+from fenics import *
 
 T = 2.0            # final time
 num_steps = 10     # number of time steps
@@ -63,11 +66,11 @@ def boundary(x, on_boundary):
 
     # Compute error at vertices
     u_e = interpolate(u_D, V)
-    error = np.abs(u_e.vector().array() - u.vector().array()).max()
+    error = np.abs(np.array(u_e.vector()) - np.array(u.vector())).max()
     print('t = %.2f: error = %.3g' % (t, error))
 
     # Update previous solution
     u_n.assign(u)
 
-# Hold plot
-interactive()
+plot(u)
+plt.show()