diff --git a/klippy/extras/tmc_uart.py b/klippy/extras/tmc_uart.py
index edcaab97b..8b304a740 100644
--- a/klippy/extras/tmc_uart.py
+++ b/klippy/extras/tmc_uart.py
@@ -71,7 +71,7 @@ class MCU_TMC_uart_bitbang:
         self.tmcuart_send_cmd = None
         self.mcu.register_config_callback(self.build_config)
     def build_config(self):
-        bit_ticks = int(self.mcu.get_adjusted_freq() / 9000.)
+        bit_ticks = self.mcu.seconds_to_clock(1. / 9000.)
         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))