diff --git a/artiq/firmware/libboard_artiq/hmc830_7043.rs b/artiq/firmware/libboard_artiq/hmc830_7043.rs
index 80b05fc4c..afa9c1c2a 100644
--- a/artiq/firmware/libboard_artiq/hmc830_7043.rs
+++ b/artiq/firmware/libboard_artiq/hmc830_7043.rs
@@ -287,11 +287,15 @@ pub mod hmc7043 {
         write(0xA0, 0xdf); // Unexplained high-performance mode
 
         // Enable required output groups
-        write(0x4, (1 << 0) |
-                   (1 << 1) |
-                   (1 << 3) |
-                   (1 << 4) |
-                   (1 << 5));
+        let mut output_group_en = 0;
+        for channel in 0..OUTPUT_CONFIG.len() {
+            let enabled = OUTPUT_CONFIG[channel].0;
+            if enabled {
+                let group = channel/2;
+                output_group_en |= 1 << group;
+            }
+        }
+        write(0x4, output_group_en);
 
         write(0x5c, (HMC_SYSREF_DIV & 0xff) as u8);  // Set SYSREF timer divider
         write(0x5d, ((HMC_SYSREF_DIV & 0x0f) >> 8) as u8);