diff --git a/artiq/firmware/libboard_artiq/hmc830_7043.rs b/artiq/firmware/libboard_artiq/hmc830_7043.rs
index 8685d46bd..f713a1380 100644
--- a/artiq/firmware/libboard_artiq/hmc830_7043.rs
+++ b/artiq/firmware/libboard_artiq/hmc830_7043.rs
@@ -30,7 +30,7 @@ mod clock_mux {
 mod hmc830 {
     use board_misoc::{csr, clock};
 
-    const HMC830_WRITES: [(u8, u32); 17] = [
+    const HMC830_WRITES: [(u8, u32); 18] = [
         (0x0, 0x20),
         (0x1, 0x2),
         (0x2, 0x2), // r_divider
@@ -39,6 +39,7 @@ mod hmc830 {
         (0x5, 0xe110),
         (0x5, 0x2818),
         (0x5, 0xf88),
+        (0x5, 0x7fb0),
         (0x5, 0x0),
         (0x6, 0x303ca),
         (0x7, 0x14d),