diff --git a/y2020/control_loops/python/flywheel.py b/y2020/control_loops/python/flywheel.py
index f284450..caaee96 100755
--- a/y2020/control_loops/python/flywheel.py
+++ b/y2020/control_loops/python/flywheel.py
@@ -205,7 +205,7 @@
     else:
         initial_t = 0
 
-    for i in xrange(iterations):
+    for i in range(iterations):
         X_hat = flywheel.X
 
         if observer_flywheel is not None: