diff --git a/system-environment/config.nix b/system-environment/config.nix
index 74680ac..2a6949f 100644
--- a/system-environment/config.nix
+++ b/system-environment/config.nix
@@ -27,12 +27,17 @@ in
 
         # Ada/+Spark & Rust tools
         alire
+        gnat15
+        gnat15Packages.gprbuild
+        gnat15Packages.gpr2
+        gnat15Packages.gnatprove
+        gnat15Packages.gnatcoll-core
+        gnat15Packages.gnatcoll-readline
+        gnat15Packages.gnatcoll-python3
         rustc
         cargo
     ];
 
-    programs.nix-ld.enable = true;
-
     environment.variables = {
     };