diff --git a/flake.nix b/flake.nix
index 60cc7a2..701bd5e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -21,7 +21,7 @@
           dontUnpack = true;
 
           buildPhase = ''
-            marp $src --output $out/presentation.html --html
+            marp $src/presentation.md --output $out/presentation.html --html
             cp -r $src/assets $out/assets
           '';
         };