diff --git a/klippy/extras/tmc_uart.py b/klippy/extras/tmc_uart.py
index 2e37cc43..b87dfca9 100644
--- a/klippy/extras/tmc_uart.py
+++ b/klippy/extras/tmc_uart.py
@@ -53,6 +53,8 @@ class MCU_analog_mux:
 # TMC uart communication
 ######################################################################
 
+TMC_BAUD_RATE = 9000
+
 # Code for sending messages on a TMC uart
 class MCU_TMC_uart_bitbang:
     def __init__(self, rx_pin_params, tx_pin_params, select_pins_desc):
@@ -71,7 +73,7 @@ class MCU_TMC_uart_bitbang:
         self.tmcuart_send_cmd = None
         self.mcu.register_config_callback(self.build_config)
     def build_config(self):
-        bit_ticks = self.mcu.seconds_to_clock(1. / 9000.)
+        bit_ticks = self.mcu.seconds_to_clock(1. / TMC_BAUD_RATE)
         self.mcu.add_config_cmd(
             "config_tmcuart oid=%d rx_pin=%s pull_up=%d tx_pin=%s bit_time=%d"
             % (self.oid, self.rx_pin, self.pullup, self.tx_pin, bit_ticks))