diff --git a/pkgs/development/compilers/iasl/default.nix b/pkgs/development/compilers/iasl/default.nix
index 36d402ee71f..e98d7cc27db 100644
--- a/pkgs/development/compilers/iasl/default.nix
+++ b/pkgs/development/compilers/iasl/default.nix
@@ -9,7 +9,7 @@ stdenv.mkDerivation rec {
     sha256 = "1ip684is3dplf7snkn024vv6bg3dv5msx8v7pz6x9lrnk3gk0j9h";
   };
 
-  NIX_CFLAGS_COMPILE = [ "-O3" ];
+  NIX_CFLAGS_COMPILE = "-O3";
 
   buildFlags = [ "iasl" ];