diff --git a/modules/common/default.nix b/modules/common/default.nix
index f708b8e..62baed8 100644
--- a/modules/common/default.nix
+++ b/modules/common/default.nix
@@ -87,7 +87,7 @@
   environment.variables = {
     EDITOR = "vim";
     HIGHLIGHT_STYLE = "solarized-light";
-    NIXPKGS_ALLOW_UNFREE = 1;
+    NIXPKGS_ALLOW_UNFREE = "1";
   };
 
   security.sudo = {
diff --git a/modules/scripts/default.nix b/modules/scripts/default.nix
new file mode 100644
index 0000000..f3010bb
--- /dev/null
+++ b/modules/scripts/default.nix
@@ -0,0 +1,7 @@
+{ pkgs, ... }:
+let
+  remove-special-characters = pkgs.writeShellScriptBin "${builtins.readFile ./remove_special_characters.sh}";
+in
+{
+  environment.systemPackages = [ remove-special-characters ];
+}
diff --git a/modules/scripts/remove_special_characters.sh b/modules/scripts/remove_special_characters.sh
new file mode 100755
index 0000000..e12402f
--- /dev/null
+++ b/modules/scripts/remove_special_characters.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+find . -print | while read file
+do
+  file_clean=${file//[ ()&\'\,]/_}
+  mv "$file" "$file_clean"
+done