diff --git a/nixos/release.nix b/nixos/release.nix
index 497056c2274..76d0ce90458 100644
--- a/nixos/release.nix
+++ b/nixos/release.nix
@@ -13,7 +13,25 @@ let
 
   forAllSystems = genAttrs supportedSystems;
 
-  callTest = fn: args: forAllSystems (system: hydraJob (import fn ({ inherit system; } // args)));
+  importTest = fn: args: system: import fn ({
+    inherit system;
+  } // args);
+
+  callTest = fn: args: forAllSystems (system: hydraJob (importTest fn args system));
+
+  callSubTests = fn: args: let
+    discover = attrs: let
+      subTests = filterAttrs (const (hasAttr "test")) attrs;
+    in mapAttrs (const (t: hydraJob t.test)) subTests;
+
+    discoverForSystem = system: mapAttrs (_: test: {
+      ${system} = test;
+    }) (discover (importTest fn args system));
+
+  # If the test is only for a particular system, use only the specified
+  # system instead of generating attributes for all available systems.
+  in if args ? system then discover (import fn args)
+     else foldAttrs (a: b: a // b) {} (map discoverForSystem supportedSystems);
 
   pkgs = import nixpkgs { system = "x86_64-linux"; };