diff --git a/app/logical/media_file/ugoira.rb b/app/logical/media_file/ugoira.rb
index 56eb9d2ae..93fac6c06 100644
--- a/app/logical/media_file/ugoira.rb
+++ b/app/logical/media_file/ugoira.rb
@@ -85,10 +85,10 @@ class MediaFile::Ugoira < MediaFile
       end
 
       ext = zipfile.first.name.match(/\.(\w{,4})$/)[1]
-      ffmpeg_out, status = Open3.capture2e("ffmpeg -i #{tmpdir}/images/%06d.#{ext} -codec:v libvpx-vp9 -crf 12 -b:v 0 -an -threads 8 -tile-columns 2 -tile-rows 1 -row-mt 1 -pass 1 -f null /dev/null")
+      ffmpeg_out, status = Open3.capture2e("ffmpeg -i #{tmpdir}/images/%06d.#{ext} -codec:v libvpx-vp9 -crf 12 -b:v 0 -an -threads 8 -tile-columns 2 -tile-rows 1 -row-mt 1 -pass 1 -passlogfile #{tmpdir}/ffmpeg2pass -f null /dev/null")
       raise Error, "ffmpeg failed: #{ffmpeg_out}" unless status.success?
 
-      ffmpeg_out, status = Open3.capture2e("ffmpeg -i #{tmpdir}/images/%06d.#{ext} -codec:v libvpx-vp9 -crf 12 -b:v 0 -an -threads 8 -tile-columns 2 -tile-rows 1 -row-mt 1 -pass 2 #{tmpdir}/tmp.webm")
+      ffmpeg_out, status = Open3.capture2e("ffmpeg -i #{tmpdir}/images/%06d.#{ext} -codec:v libvpx-vp9 -crf 12 -b:v 0 -an -threads 8 -tile-columns 2 -tile-rows 1 -row-mt 1 -pass 2 -passlogfile #{tmpdir}/ffmpeg2pass #{tmpdir}/tmp.webm")
       raise Error, "ffmpeg failed: #{ffmpeg_out}" unless status.success?
 
       mkvmerge_out, status = Open3.capture2e("mkvmerge -o #{output_file.path} --webm --timecodes 0:#{tmpdir}/timecodes.tc #{tmpdir}/tmp.webm")