diff --git a/src/invidious/routes/video_playback.cr b/src/invidious/routes/video_playback.cr
index f24c0ded..9641e01a 100644
--- a/src/invidious/routes/video_playback.cr
+++ b/src/invidious/routes/video_playback.cr
@@ -278,7 +278,7 @@ module Invidious::Routes::VideoPlayback
     end
 
     if itag.nil?
-      fmt = video.fmt_stream[-1]
+      fmt = video.fmt_stream[-1]?
     else
       fmt = video.fmt_stream.find(nil) { |f| f["itag"].as_i == itag } || video.adaptive_fmts.find(nil) { |f| f["itag"].as_i == itag }
     end