diff --git a/pkgs/applications/misc/audio/sox/default.nix b/pkgs/applications/misc/audio/sox/default.nix
index 0663937c479..1f86a4164f6 100644
--- a/pkgs/applications/misc/audio/sox/default.nix
+++ b/pkgs/applications/misc/audio/sox/default.nix
@@ -4,6 +4,8 @@
 , enableLame ? false, lame ? null
 , enableLibmad ? true, libmad ? null
 , enableLibogg ? true, libogg ? null, libvorbis ? null
+, enableFLAC ? true, flac ? null
+, enablePNG ? true, libpng ? null
 }:
 
 with stdenv.lib;
@@ -21,7 +23,9 @@ stdenv.mkDerivation rec {
     optional enableLibao libao ++
     optional enableLame lame ++
     optional enableLibmad libmad ++
-    optionals enableLibogg [ libogg libvorbis ];
+    optionals enableLibogg [ libogg libvorbis ] ++
+    optional enableFLAC flac ++
+    optional enablePNG libpng;
 
   meta = {
     description = "Sample Rate Converter for audio";