diff --git a/apps/isabelle.nix b/apps/isabelle-upstream.nix
similarity index 93%
rename from apps/isabelle.nix
rename to apps/isabelle-upstream.nix
index 186b49f..aee6029 100644
--- a/apps/isabelle.nix
+++ b/apps/isabelle-upstream.nix
@@ -8,7 +8,7 @@ let
   };
 in
 buildFHSEnv {
-  pname = "isabelle";
+  pname = "isabelle-upstream";
   inherit version;
   targetPkgs = pkgs:
     (with pkgs;      [ zlib fontconfig ]) ++
diff --git a/flake.nix b/flake.nix
index 833e876..a55befc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -11,11 +11,12 @@
       genAttrs names (pkg: callPackage ./${dir}/${pkg}.nix {});
 
     linuxPackages = packagesInDir "apps" [
-      "multi-ghc" "basilisk" "isabelle"
+      "multi-ghc" "basilisk" "isabelle-upstream"
       "firefox-esr-alias" "inkscape-xwayland"
     ];
 
-    crossPlatformPackages = packagesInDir "scripts" [ "niss-misc" ];
+    crossPlatformPackages =
+      packagesInDir "scripts" [ "niss-misc" ];
 
     fonts = packagesInDir "fonts" [
       "constructium" "fairfax-hd" "kreative-square" "muller"