diff --git a/y2020/constants.cc b/y2020/constants.cc
index 4d9d066..6218f9b 100644
--- a/y2020/constants.cc
+++ b/y2020/constants.cc
@@ -12,6 +12,9 @@
 
 #include "aos/network/team_number.h"
 #include "aos/stl_mutex/stl_mutex.h"
+#include "frc971/zeroing/absolute_and_absolute_encoder.h"
+#include "frc971/zeroing/absolute_encoder.h"
+#include "frc971/zeroing/pot_and_absolute_encoder.h"
 #include "y2020/control_loops/superstructure/control_panel/integral_control_panel_plant.h"
 #include "y2020/control_loops/superstructure/hood/integral_hood_plant.h"
 #include "y2020/control_loops/superstructure/intake/integral_intake_plant.h"