diff --git a/pkgs/tools/archivers/zpaq/default.nix b/pkgs/tools/archivers/zpaq/default.nix
index 832f8a4f8c5..44f318a0cc6 100644
--- a/pkgs/tools/archivers/zpaq/default.nix
+++ b/pkgs/tools/archivers/zpaq/default.nix
@@ -20,9 +20,9 @@ stdenv.mkDerivation rec {
       + (lib.optionalString (!isi686 && !isx86_64) "-DNOJIT ")
       + "-Dunix";
     CXXFLAGS = with stdenv; ""
-      + (lib.optionalString (isi686) "-march=i686 ")
-      + (lib.optionalString (isx86_64) "-march=nocona ")
-      + "-O3 -mtune=generic -DNDEBUG";
+      + (lib.optionalString isi686   "-march=i686   -mtune=generic ")
+      + (lib.optionalString isx86_64 "-march=nocona -mtune=generic ")
+      + "-O3 -DNDEBUG";
   in ''
     buildFlagsArray=( "CPPFLAGS=${CPPFLAGS}" "CXXFLAGS=${CXXFLAGS}" )
   '';