diff --git a/pkgs/by-name/br/bruijn/generated.nix b/pkgs/by-name/br/bruijn/generated.nix
index 573a0f78f0b3..4f1bf046f911 100644
--- a/pkgs/by-name/br/bruijn/generated.nix
+++ b/pkgs/by-name/br/bruijn/generated.nix
@@ -22,7 +22,7 @@
 }:
 mkDerivation {
   pname = "bruijn";
-  version = "0.1.0.0";
+  version = "0-unstable-2025-11-01";
   src = fetchzip {
     url = "https://github.com/marvinborner/bruijn/archive/c37a9d27b9f654b1e0118d32269a1548800b062b.tar.gz";
     sha256 = "1a667693agsc559yy4k04gxv1hlsgkn3aw64yvg876fbn5dr7sk3";
diff --git a/pkgs/by-name/br/bruijn/package.nix b/pkgs/by-name/br/bruijn/package.nix
index 981b57465a8e..f0f8efd2c3c2 100644
--- a/pkgs/by-name/br/bruijn/package.nix
+++ b/pkgs/by-name/br/bruijn/package.nix
@@ -10,8 +10,6 @@ let
   generated = haskellPackages.callPackage ./generated.nix { };
 
   overrides = {
-    version = lib.fileContents ./version.txt;
-
     passthru.updateScript = ./update.sh;
 
     description = "Purely functional programming language based on lambda calculus and de Bruijn indices";
diff --git a/pkgs/by-name/br/bruijn/update.sh b/pkgs/by-name/br/bruijn/update.sh
index 837a3a680170..d5c0c1ae3ea4 100755
--- a/pkgs/by-name/br/bruijn/update.sh
+++ b/pkgs/by-name/br/bruijn/update.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#!nix-shell -i bash -p coreutils cabal2nix curl jq
+#!nix-shell -i bash -p coreutils cabal2nix curl jq nixfmt gnused
 
 set -euo pipefail
 
@@ -9,8 +9,9 @@ cd "$(dirname "${BASH_SOURCE[0]}")"
   < <(curl ${GITHUB_TOKEN:+-u ":$GITHUB_TOKEN"} -sfL https://api.github.com/repos/marvinborner/bruijn/branches/main \
     | jq -r '.commit | .sha, .commit.committer.date')
 
+version="0-unstable-$(date -I --date="$committer_date")"
+
 cabal2nix --maintainer defelo "https://github.com/marvinborner/bruijn/archive/${rev}.tar.gz" \
   | nixfmt \
+  | sed -E 's/\bversion = "[^"]+";/version = "'"${version}"'";/' \
   > generated.nix
-
-echo "0-unstable-$(date -I --date="$committer_date")" > version.txt
diff --git a/pkgs/by-name/br/bruijn/version.txt b/pkgs/by-name/br/bruijn/version.txt
deleted file mode 100644
index 7b5b0a92b554..000000000000
--- a/pkgs/by-name/br/bruijn/version.txt
+++ /dev/null
@@ -1 +0,0 @@
-0-unstable-2025-11-01