diff --git a/lib/colmenaSystem.nix b/lib/colmenaSystem.nix
index f5076cde..fc54b39e 100644
--- a/lib/colmenaSystem.nix
+++ b/lib/colmenaSystem.nix
@@ -23,9 +23,7 @@ in
         {
           # make `nix run nixpkgs#nixpkgs` use the same nixpkgs as the one used by this flake.
           nix.registry.nixpkgs.flake = nixpkgs;
-          # make `nix repl '<nixpkgs>'` use the same nixpkgs as the one used by this flake.
-          environment.etc."nix/inputs/nixpkgs".source = "${nixpkgs}";
-          nix.nixPath = ["/etc/nix/inputs"];
+          nix.channel.enable = false;  # disable nix-channel, we use flakes instead.
         }
       ] ++ (if (home-module != null) then [
         home-manager.nixosModules.home-manager
diff --git a/lib/macosSystem.nix b/lib/macosSystem.nix
index 6aa77c50..2cc6e410 100644
--- a/lib/macosSystem.nix
+++ b/lib/macosSystem.nix
@@ -14,14 +14,15 @@ in
     modules =
       darwin-modules
       ++ [
-        {
+        ({lib, ...}: {
           # make `nix run nixpkgs#nixpkgs` use the same nixpkgs as the one used by this flake.
           nix.registry.nixpkgs.flake = nixpkgs;
 
-          # make `nix repl '<nixpkgs>'` use the same nixpkgs as the one used by this flake.
           environment.etc."nix/inputs/nixpkgs".source = "${nixpkgs}";
-          nix.nixPath = ["/etc/nix/inputs"];
-        }
+          # make `nix repl '<nixpkgs>'` use the same nixpkgs as the one used by this flake.
+          # discard all the default paths, and only use the one from this flake.
+          nix.nixPath = lib.mkForce ["/etc/nix/inputs"];
+        })
 
         home-manager.darwinModules.home-manager
         {
diff --git a/lib/nixosSystem.nix b/lib/nixosSystem.nix
index 0cdc157e..15371319 100644
--- a/lib/nixosSystem.nix
+++ b/lib/nixosSystem.nix
@@ -17,10 +17,7 @@ in
         {
           # make `nix run nixpkgs#nixpkgs` use the same nixpkgs as the one used by this flake.
           nix.registry.nixpkgs.flake = nixpkgs;
-
-          # make `nix repl '<nixpkgs>'` use the same nixpkgs as the one used by this flake.
-          environment.etc."nix/inputs/nixpkgs".source = "${nixpkgs}";
-          nix.nixPath = ["/etc/nix/inputs"];
+          nix.channel.enable = false;  # disable nix-channel, we use flakes instead.
         }
 
         nixos-generators.nixosModules.all-formats