diff --git a/hydra/jobsets.nix b/hydra/jobsets.nix
index 013d97f..c94126b 100644
--- a/hydra/jobsets.nix
+++ b/hydra/jobsets.nix
@@ -7,39 +7,42 @@
   systems = ["x86_64-linux" "aarch64-linux" "riscv64-linux"];
   nixpkgs_version = ["master" "nixos-22.05"];
   mkJobsets = system: version:
-    (pkgs.lib.mapAttrs (
+    (pkgs.lib.mapAttrs' (
         num: info: {
-          enabled = 1;
-          hidden = false;
-          description = "PR ${num} (${system}-${version}): ${info.title}";
-          nixexprinput = "nix-packages";
-          nixexprpath = "hydra/default.nix";
-          checkinterval = 60;
-          schedulingshares = 100;
-          enableemail = false;
-          emailoverride = "";
-          keepnr = 1;
-          inputs = {
-            nix-packages = {
-              type = "git";
-              value = "https://github.com/${info.head.repo.owner.login}/${info.head.repo.name}.git ${info.head.ref}";
-              emailresponsible = false;
-            };
-            nixpkgs = {
-              type = "git";
-              value = "https://github.com/NixOS/nixpkgs.git ${version}";
-              emailresponsible = false;
-            };
-            system = {
-              type = "string";
-              value = system;
+          name = "${system}-${version}-pr${num}";
+          value = {
+            enabled = 1;
+            hidden = false;
+            description = "PR ${num} (${system}-${version}): ${info.title}";
+            nixexprinput = "nix-packages";
+            nixexprpath = "hydra/default.nix";
+            checkinterval = 60;
+            schedulingshares = 100;
+            enableemail = false;
+            emailoverride = "";
+            keepnr = 1;
+            inputs = {
+              nix-packages = {
+                type = "git";
+                value = "https://github.com/${info.head.repo.owner.login}/${info.head.repo.name}.git ${info.head.ref}";
+                emailresponsible = false;
+              };
+              nixpkgs = {
+                type = "git";
+                value = "https://github.com/NixOS/nixpkgs.git ${version}";
+                emailresponsible = false;
+              };
+              system = {
+                type = "string";
+                value = system;
+              };
             };
           };
         }
       )
       prs)
     // {
-      main = {
+      "${system}-${version}" = {
         enabled = 1;
         hidden = false;
         description = "nix-packages ${system}-${version}";
@@ -69,17 +72,7 @@
       };
     };
 
-  mapToAttrs = f: list: pkgs.lib.listToAttrs (map f list);
+  concatAttrs = pkgs.lib.foldr (a: b: a // b) {};
 
-  jobsets =
-    mapToAttrs (system: {
-      name = system;
-      value =
-        mapToAttrs (version: {
-          name = version;
-          value = mkJobsets system version;
-        })
-        nixpkgs_version;
-    })
-    systems;
+  jobsets = concatAttrs (pkgs.lib.concatMap (system: map (version: mkJobsets system version) nixpkgs_version) systems);
 in {jobsets = pkgs.writeText "jobsets.json" (builtins.toJSON jobsets);}