diff --git a/contrib/nix/README b/contrib/nix/README
index e56874c2..beacb1bc 100644
--- a/contrib/nix/README
+++ b/contrib/nix/README
@@ -1,3 +1,7 @@
 After updating Gemfile, regenerate Gemfile.lock and gemset.nix:
 
     nix-shell -p bundix --run 'bundix --gemfile=contrib/nix/Gemfile --lockfile=contrib/nix/Gemfile.lock --gemset=contrib/nix/gemset.nix -l'
+
+Test gem installation:
+
+    nix-shell contrib/nix/gem-install-shell.nix --run 'gem install --verbose -i ./asdf ./pkg/sup-999.gem'
diff --git a/contrib/nix/gem-install-shell.nix b/contrib/nix/gem-install-shell.nix
new file mode 100644
index 00000000..b808ec3b
--- /dev/null
+++ b/contrib/nix/gem-install-shell.nix
@@ -0,0 +1,12 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShell {
+  packages = with pkgs; [
+    ncurses
+    ncurses.dev
+    libuuid
+    libuuid.dev
+    ruby_3_2
+    zlib
+    zlib.dev
+  ];
+}