diff --git a/pkgs/tools/graphics/vulkan-extension-layer/default.nix b/pkgs/tools/graphics/vulkan-extension-layer/default.nix
index 68ef3eddee5..a80e216137d 100644
--- a/pkgs/tools/graphics/vulkan-extension-layer/default.nix
+++ b/pkgs/tools/graphics/vulkan-extension-layer/default.nix
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
 
   # Help vulkan-loader find the validation layers
   setupHook = writeText "setup-hook" ''
-    export XDG_DATA_DIRS=@out@/share:$XDG_DATA_DIRS
+    addToSearchPath XDG_DATA_DIRS @out@/share
   '';
 
   # Tests are not for gpu-less and headless environments