diff --git a/README.md b/README.md
index b13cb79..f1a53f6 100644
--- a/README.md
+++ b/README.md
@@ -109,6 +109,7 @@ custom_color=rgba(193,125,17,1)
 
 - **Copy**: If you don't have [wl-clipboard] installed, copy to clipboard won't work if you close swappy (the content of the clipboard is lost). This because GTK 3.24 [has not implemented persistent storage on wayland backend yet](https://gitlab.gnome.org/GNOME/gtk/blob/3.24.13/gdk/wayland/gdkdisplay-wayland.c#L857). We need to do it on the [Wayland level](https://github.com/swaywm/wlr-protocols/blob/master/unstable/wlr-data-control-unstable-v1.xml), or wait for GTK 4. For now, we use `wl-copy` if installed and revert to `gtk` clipboard if not found.
 - **Fonts**: Swappy relies on Font Awesome 5 being present to properly render the icons. On Arch you can simply install those with: `sudo pacman -S otf-font-awesome`
+- **Output Format**: Only PNG is supported.
 
 ## Installation