diff --git a/flake.nix b/flake.nix
index 49dcd9056..212f68144 100644
--- a/flake.nix
+++ b/flake.nix
@@ -128,6 +128,9 @@
           cargo-insta
           cargo-nextest
           cargo-watch
+
+          # For building the documentation website
+          poetry
         ];
 
         shellHook = ''