diff --git a/pkgs/tools/networking/slack-cli/default.nix b/pkgs/tools/networking/slack-cli/default.nix
index dc8b25d868c8..18f192d3535f 100644
--- a/pkgs/tools/networking/slack-cli/default.nix
+++ b/pkgs/tools/networking/slack-cli/default.nix
@@ -7,41 +7,42 @@
 
 { stdenv, lib, writeShellScriptBin, fetchFromGitHub, curl, jq }:
 
-let
-  wrapper = writeShellScriptBin "slack" ''
-    [ "$1" = "init" -a -z "$SLACK_CLI_TOKEN" ] && cat >&2 <<-'MESSAGE'
-    WARNING: slack-cli must be configured using the SLACK_CLI_TOKEN environment
-    variable. Using `slack init` will not work because it tries to write to the
-    Nix store.
+stdenv.mkDerivation rec {
+  name = "slack-cli-${version}";
+  version = "0.18.0";
+
+  src = fetchFromGitHub {
+    owner = "rockymadden";
+    repo = "slack-cli";
+    rev = "v${version}";
+    sha256 = "022yr3cpfg0v7cxi62zzk08vp0l3w851qpfh6amyfgjiynnfyddl";
+  };
+
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p "$out/bin"
+    cp src/slack "$out/bin/.slack-wrapped"
+
+    cat <<-WRAPPER > "$out/bin/slack"
+    #!${stdenv.shell}
+    [ "\$1" = "init" -a -z "\$SLACK_CLI_TOKEN" ] && cat <<-'MESSAGE' >&2
+    WARNING: slack-cli must be configured using the SLACK_CLI_TOKEN
+    environment variable. Using \`slack init\` will not work because it tries
+    to write to the Nix store.
 
     MESSAGE
 
-    export PATH=${lib.makeBinPath [ curl jq ]}:"$PATH"
-    exec "$(dirname "$0")/.slack-wrapped" "$@"
+    export PATH=${lib.makeBinPath [ curl jq ]}:"\$PATH"
+    exec "$out/bin/.slack-wrapped" "\$@"
+    WRAPPER
+
+    chmod +x "$out/bin/slack"
   '';
 
-in stdenv.mkDerivation rec {
-    name = "slack-cli-${version}";
-    version = "0.18.0";
-
-    src = fetchFromGitHub {
-      owner = "rockymadden";
-      repo = "slack-cli";
-      rev = "v${version}";
-      sha256 = "022yr3cpfg0v7cxi62zzk08vp0l3w851qpfh6amyfgjiynnfyddl";
-    };
-
-    dontBuild = true;
-
-    installPhase = ''
-      mkdir -p "$out/bin"
-      cp src/slack "$out/bin/.slack-wrapped"
-      ln -s ${wrapper}/bin/slack "$out/bin/slack"
-    '';
-
-    meta = {
-      license = lib.licenses.mit;
-      maintainers = [ lib.maintainers.qyliss ];
-      platforms = lib.platforms.unix;
-    };
-  }
+  meta = {
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.qyliss ];
+    platforms = lib.platforms.unix;
+  };
+}