diff --git a/shell.nix b/shell.nix
index 02a392e56..f5193d6cf 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,4 +1,5 @@
 { lib
+, mdbook
 , nannou
 , mkShell
 , stdenv
@@ -6,6 +7,7 @@
 mkShell {
   name = "nannou-dev";
   inputsFrom = [ nannou ];
+  buildInputs = [ mdbook ];
   env = (lib.optionalAttrs stdenv.isLinux
     {
       inherit (nannou) ALSA_LIB_DEV LD_LIBRARY_PATH XCURSOR_THEME;