diff --git a/config/default.yaml b/config/default.yaml
index ad0e6084b..5a83b271e 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -140,6 +140,7 @@ transcoding:
     720p: false
     1080p: false
   # /!\ EXPERIMENTAL /!\
+  # /!\ Requires ffmpeg >= 3.4
   # Generate HLS playlist/segments. Better playback than with WebTorrent:
   #     * Resolution change is smoother
   #     * Faster playback in particular with long videos
diff --git a/config/production.yaml.example b/config/production.yaml.example
index 98734bab6..c54e1a516 100644
--- a/config/production.yaml.example
+++ b/config/production.yaml.example
@@ -153,6 +153,7 @@ transcoding:
     720p: false
     1080p: false
   # /!\ EXPERIMENTAL /!\
+  # /!\ Requires ffmpeg >= 3.4
   # Generate HLS playlist/segments. Better playback than with WebTorrent:
   #     * Resolution change is smoother
   #     * Faster playback in particular with long videos