diff --git a/shell.nix b/shell.nix
index d95466a..dcde169 100644
--- a/shell.nix
+++ b/shell.nix
@@ -4,6 +4,7 @@ pkgs.mkShell {
   buildInputs = with pkgs; [
     imagemagick
     just
+    libavif
     pandoc
     tup
   ];