diff --git a/frc971/control_loops/python/controls.py b/frc971/control_loops/python/controls.py
index ed6a809..211b478 100644
--- a/frc971/control_loops/python/controls.py
+++ b/frc971/control_loops/python/controls.py
@@ -89,7 +89,8 @@
   """Converts from continuous time state space representation to discrete time.
      Returns (A, B).  C and D are unchanged."""
 
-  ans_a, ans_b, _, _, _ = scipy.signal.cont2discrete((A, B, None, None), dt)
+  ans_a, ans_b, _, _, _ = scipy.signal.cont2discrete(
+      (numpy.array(A), numpy.array(B), None, None), dt)
   return numpy.matrix(ans_a), numpy.matrix(ans_b)
 
 def ctrb(A, B):