diff --git a/artiq/coredevice/i2c.py b/artiq/coredevice/i2c.py
index 2b3be2bc7..13c309527 100644
--- a/artiq/coredevice/i2c.py
+++ b/artiq/coredevice/i2c.py
@@ -161,6 +161,7 @@ class I2CSwitch:
     @kernel
     def set(self, channel):
         """Enable one channel.
+
         :param channel: channel number (0-7)
         """
         i2c_switch_select(self.busno, self.address >> 1, 1 << channel)