diff --git a/overlay.nix b/overlay.nix
index 431cfe6..1888a05 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -72,14 +72,19 @@ override_2_18 //
   nix-eval-jobs = (prev.nix-eval-jobs.override {
     # lix
     nix = final.nixVersions.nix_2_18;
-  }).overrideAttrs (old: {
-    # FIXME: should this be patches instead?
-    src = final.lix-sources.nix-eval-jobs;
+  }).overrideAttrs (old:
+    let src = final.lix-sources.nix-eval-jobs;
+    in {
+      version = "2.90.0-lix-${builtins.substring 0 7 src.rev}";
 
-    mesonBuildType = "debugoptimized";
+      # FIXME: should this be patches instead?
+      inherit src;
 
-    ninjaFlags = old.ninjaFlags or [ ] ++ [ "-v" ];
-  });
+      mesonBuildType = "debugoptimized";
+
+      ninjaFlags = old.ninjaFlags or [ ] ++ [ "-v" ];
+    }
+  );
 
   # support both having and missing https://github.com/NixOS/nixpkgs/pull/304913
   prefetch-npm-deps =
diff --git a/pins.nix b/pins.nix
index 6027932..77b70be 100644
--- a/pins.nix
+++ b/pins.nix
@@ -14,11 +14,13 @@ let
           narHash = args.nar_hash;
         }
     else if kind == "tarball" then
-      builtins.fetchTarball
-        {
+      args // {
+        outPath = builtins.fetchTarball {
           name = "source";
           url = args.locked_url;
           sha256 = args.nar_hash;
-        } else builtins.throw "unsupported input type ${kind}";
+        };
+      }
+    else builtins.throw "unsupported input type ${kind}";
 in
 builtins.mapAttrs (_: fetchPin) pins