diff --git a/shell.nix b/shell.nix
index f4bf32107..dfe47c7a0 100644
--- a/shell.nix
+++ b/shell.nix
@@ -192,8 +192,42 @@ let
       echo "In develop"
     fi
   '';
+
+  killallUni2work = pkgs.writeScriptBin "killall-uni2work" ''
+    #!${pkgs.zsh}/bin/zsh
+
+    set -o pipefail
+
+    lockFile=
+
+    if [[ ''${#@} -gt 0 ]]; then
+      lockFile=''${1}
+      shift
+
+      if [[ -d ''${lockFile} && -f ''${lockFile}/.stack-work.lock ]]; then
+        lockFile=''${lockFile}/.stack-work.lock
+      fi
+    else
+      if [[ -f .stack-work.lock ]]; then
+        lockFile=.stack-work.lock
+      elif [[ -f ~/projects/uni2work/.stack-work.lock ]]; then
+        lockFile=~/projects/uni2work/.stack-work.lock
+      fi
+    fi
+
+    if [[ -z "''${lockFile}" && !(-f ''${lockFile}) ]]; then
+      echo "Could not find lockfile" >&2
+      exit 1
+    fi
+
+    printf "Killing users of %s...\n" ''${lockFile}
+
+    while ${pkgs.psmisc}/bin/fuser ''${lockFile} 2>/dev/null | ${pkgs.coreutils}/bin/cut -d ':' -f 2- | ${pkgs.findutils}/bin/xargs -tr -- ${pkgs.util-linux}/bin/kill; do
+      sleep 1
+    done
+  '';
 in pkgs.mkShell {
   name = "uni2work";
   
-  nativeBuildInputs = [develop inDevelop] ++ (with pkgs; [ nodejs-14_x postgresql_12 openldap google-chrome exiftool memcached minio minio-client gup ]) ++ (with pkgs.haskellPackages; [ stack yesod-bin hlint cabal-install weeder profiteur ]);
+  nativeBuildInputs = [develop inDevelop killallUni2work] ++ (with pkgs; [ nodejs-14_x postgresql_12 openldap google-chrome exiftool memcached minio minio-client gup ]) ++ (with pkgs.haskellPackages; [ stack yesod-bin hlint cabal-install weeder profiteur ]);
 }