diff --git a/users/aspen/system/home/modules/development.nix b/users/aspen/system/home/modules/development.nix
index 311941766..ca6ef131a 100644
--- a/users/aspen/system/home/modules/development.nix
+++ b/users/aspen/system/home/modules/development.nix
@@ -52,6 +52,7 @@ with lib;
     jsonnet
     ngrok
     amber
+    ocamlPackages.patdiff
 
     gdb
     lldb