diff --git a/pkgs/os-specific/linux/rtl8723bs/default.nix b/pkgs/os-specific/linux/rtl8723bs/default.nix
index b1e01f705dcf..f468196dc73d 100644
--- a/pkgs/os-specific/linux/rtl8723bs/default.nix
+++ b/pkgs/os-specific/linux/rtl8723bs/default.nix
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ nukeReferences ];
 
-  makeFlags = concatStringsSep " " [
+  makeFlags = [
     "ARCH=${stdenv.hostPlatform.platform.kernelArch}" # Normally not needed, but the Makefile sets ARCH in a broken way.
     "KSRC=${kernel.dev}/lib/modules/${kernel.modDirVersion}/build" # Makefile uses $(uname -r); breaks us.
   ];