diff --git a/pkgs/applications/audio/flac/default.nix b/pkgs/applications/audio/flac/default.nix
index 644a19c0f040..bebb35f45009 100644
--- a/pkgs/applications/audio/flac/default.nix
+++ b/pkgs/applications/audio/flac/default.nix
@@ -33,6 +33,9 @@ stdenv.mkDerivation rec {
     "-DBUILD_SHARED_LIBS=ON"
   ];
 
+  CFLAGS = [ "-O3" "-funroll-loops" ];
+  CXXFLAGS = [ "-O3" ];
+
   # doCheck = true; # takes lots of time
 
   outputs = [ "bin" "dev" "out" "man" "doc" ];