diff --git a/artiq/coredevice/suservo.py b/artiq/coredevice/suservo.py
index 48cc013fc..28feba4ec 100644
--- a/artiq/coredevice/suservo.py
+++ b/artiq/coredevice/suservo.py
@@ -12,7 +12,7 @@ WE = 1 << COEFF_DEPTH + 1
 STATE_SEL = 1 << COEFF_DEPTH
 CONFIG_SEL = 1 << COEFF_DEPTH - 1
 CONFIG_ADDR = CONFIG_SEL | STATE_SEL
-T_CYCLE = (2*(8 + 64) + 2 + 1)*8*ns
+T_CYCLE = (2*(8 + 64) + 2)*8*ns  # Must match gateware Servo.t_cycle.
 COEFF_SHIFT = 11