diff --git a/artiq/coredevice/phaser.py b/artiq/coredevice/phaser.py
index 0bb468e23..3f5e4262c 100644
--- a/artiq/coredevice/phaser.py
+++ b/artiq/coredevice/phaser.py
@@ -1067,7 +1067,7 @@ class PhaserChannel:
         """
         if (profile < 0) | (profile > 3):
             raise ValueError("invalid profile index")
-        addr = PHASER_ADDR_SERVO_CFG1 if self.index == 1 else PHASER_ADDR_SERVO_CFG0
+        addr = PHASER_ADDR_SERVO_CFG0 + self.index
         if bypass == 0:
             data = 1
         if hold == 1: