diff --git a/docs/default.nix b/docs/default.nix
index 7846d987f..b6dae7092 100644
--- a/docs/default.nix
+++ b/docs/default.nix
@@ -7,7 +7,10 @@
 
 let
 
-  nmdSrc = pkgs.nix-lib-nmd;
+  nmdSrc = fetchTarball {
+    url = "https://git.sr.ht/~rycee/nmd/archive/v0.5.0.tar.gz";
+    sha256 = "0hnd86jd19zb5j3hmpwmdmdiasg65lgahqv7n8frl9p1vdqz6z67";
+  };
 
   nmd = import nmdSrc {
     inherit lib;
diff --git a/tests/default.nix b/tests/default.nix
index 8b5bdfde1..b9874d8b5 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -4,6 +4,11 @@ let
 
   lib = import ../modules/lib/stdlib-extended.nix pkgs.lib;
 
+  nmtSrc = fetchTarball {
+    url = "https://git.sr.ht/~rycee/nmt/archive/v0.5.1.tar.gz";
+    sha256 = "0qhn7nnwdwzh910ss78ga2d00v42b0lspfd7ybl61mpfgz3lmdcj";
+  };
+
   modules = import ../modules/modules.nix {
     inherit lib pkgs;
     check = false;
@@ -33,7 +38,7 @@ let
   isDarwin = pkgs.stdenv.hostPlatform.isDarwin;
   isLinux = pkgs.stdenv.hostPlatform.isLinux;
 
-in import pkgs.nix-lib-nmt {
+in import nmtSrc {
   inherit lib pkgs modules;
   testedAttrPath = [ "home" "activationPackage" ];
   tests = builtins.foldl' (a: b: a // (import b)) { } ([