diff --git a/src/libboard_artiq/src/drtioaux_proto.rs b/src/libboard_artiq/src/drtioaux_proto.rs
index c83da1d..e2fee29 100644
--- a/src/libboard_artiq/src/drtioaux_proto.rs
+++ b/src/libboard_artiq/src/drtioaux_proto.rs
@@ -308,7 +308,7 @@ impl Packet {
                 writer.write_u8(0x87)?;
                 writer.write_bool(succeeded)?;
             },
-            Packet::I2cPca954xSelectRequest { destination, busno, address, mask } => {
+            Packet::I2cSwitchSelectRequest { destination, busno, address, mask } => {
                 writer.write_u8(0x88)?;
                 writer.write_u8(destination)?;
                 writer.write_u8(busno)?;
diff --git a/src/runtime/src/i2c.rs b/src/runtime/src/i2c.rs
index b2c166f..de908f3 100644
--- a/src/runtime/src/i2c.rs
+++ b/src/runtime/src/i2c.rs
@@ -64,19 +64,19 @@ pub extern fn switch_select(busno: i32, address: i32, mask: i32) {
     if busno > 0 {
         artiq_raise!("I2CError", "I2C bus could not be accessed");
     }
+    let ch = match mask { //decode from mainline, PCA9548-centric API
+        0x00 => None,
+        0x01 => Some(0),
+        0x02 => Some(1),
+        0x04 => Some(2),
+        0x08 => Some(3),
+        0x10 => Some(4),
+        0x20 => Some(5),
+        0x40 => Some(6),
+        0x80 => Some(7),
+        _ => artiq_raise!("I2CError", "switch select supports only one channel")
+    };
     unsafe {
-        let ch = match mask { //decode from mainline, PCA9548-centric API
-            0x00 => None,
-            0x01 => Some(0),
-            0x02 => Some(1),
-            0x04 => Some(2),
-            0x08 => Some(3),
-            0x10 => Some(4),
-            0x20 => Some(5),
-            0x40 => Some(6),
-            0x80 => Some(7),
-            _ => { artiq_raise!("I2CError", "switch select supports only one channel"); return }
-        };
         if (&mut I2C_BUS).as_mut().unwrap().pca954x_select(address as u8, ch).is_err() {
             artiq_raise!("I2CError", "switch select failed");
         }