diff --git a/services/capture/src/capture-manager.js b/services/capture/src/capture-manager.js
index 9ed65db..5c4b5e5 100644
--- a/services/capture/src/capture-manager.js
+++ b/services/capture/src/capture-manager.js
@@ -673,6 +673,7 @@ class CaptureManager {
     // recorded duration grows mid-write.
     const bmx = [
       'raw2bmx', '-t', 'op1a', '-o', '"$OUT"', '-f', frameRate,
+      '--growing-file',
       '--part', String(GROWING_PART_INTERVAL_FRAMES),
       rawFlag, '"$VF"',
       '-s', '48000', '-q', '16', '--audio-chan', String(ach), '--pcm', '"$AF"',