diff --git a/scripts/8_merged_to_mp4.sh b/scripts/8_merged_to_mp4.sh
index f048453..39eb81c 100755
--- a/scripts/8_merged_to_mp4.sh
+++ b/scripts/8_merged_to_mp4.sh
@@ -2,7 +2,7 @@
 cd "$(dirname $0)/.."
 source scripts/env.sh
 
-python "$DFL_MAIN" videoed video-from-sequence \
+python3.9 "$DFL_MAIN" videoed video-from-sequence \
   --input-dir "$WORKSPACE/data_dst/merged" \
   --output-file "$WORKSPACE/result.mp4" \
   --reference-file "$WORKSPACE/data_dst.*" \