diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2e75543d3..22214e93c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -92,7 +92,7 @@ backend dependencies:
         - .stack
         - .stack-work
   script:
-    - "nix shell .#gnumake .#stack .#coreutils --command sh -c 'prepare-env && make backend-dependencies'" # TODO maybe remove prepare-env
+    - "nix shell .#gnumake .#stack .#coreutils .#prepareEnv --command sh -c 'prepare-env && make backend-dependencies'" # TODO maybe remove prepare-env
     - "ls -a ." # TODO: debug only
     - "ls -a ${HOME}/.stack"
   before_script: *nix-before
diff --git a/shell.nix b/shell.nix
index 752198903..cc5d54702 100644
--- a/shell.nix
+++ b/shell.nix
@@ -264,7 +264,7 @@ let
   '';
 
   prepareEnv = pkgs.writeScriptBin "prepare-env" ''
-    #!${pkgs.zsh}/bin/zsh
+    #!/bin/sh
 
     export TZDIR=${pkgs.tzdata}/share/zoneinfo
     export CHROME_BIN=${pkgs.chromium}/bin/chromium