diff --git a/card10-l0dable/src/max86150.rs b/card10-l0dable/src/max86150.rs
index 0a808842a71f0b1650dd434a603e289bdae12bc6..476918e5755024b4a65e29cd3abf722231c0b553 100644
--- a/card10-l0dable/src/max86150.rs
+++ b/card10-l0dable/src/max86150.rs
@@ -22,10 +22,9 @@ impl MAX86150 {
         let mut cfg = max86150_sensor_config {
             sample_buffer_len: DATA_MAX,
             ppg_sample_rate: 200,
-            _padding: [0u8; 10],
         };
 
-        let stream_id = unsafe { epic_max86150_enable_sensor(&mut cfg) };
+        let stream_id = unsafe { epic_max86150_enable_sensor(&mut cfg,  size_of::<max86150_sensor_config>()) };
 
         if stream_id < 0 {
             let error = match -stream_id {