diff --git a/pkgs/applications/audio/vorbis-tools/default.nix b/pkgs/applications/audio/vorbis-tools/default.nix
index 46e67c7dc33e..877f670d6861 100644
--- a/pkgs/applications/audio/vorbis-tools/default.nix
+++ b/pkgs/applications/audio/vorbis-tools/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, libogg, libvorbis, libao, pkg-config, curl
+{ lib, stdenv, fetchurl, fetchpatch, libogg, libvorbis, libao, pkg-config, curl, libiconv
 , speex, flac
 , autoreconfHook }:
 
@@ -11,12 +11,18 @@ stdenv.mkDerivation rec {
     sha256 = "1c7h4ivgfdyygz2hyh6nfibxlkz8kdk868a576qkkjgj5gn78xyv";
   };
 
-  nativeBuildInputs = [ autoreconfHook pkg-config ];
-  buildInputs = [ libogg libvorbis libao curl speex flac ];
+  patches = lib.optionals stdenv.cc.isClang [
+    # Fixes a call to undeclared function `utf8_decode`.
+    # https://github.com/xiph/vorbis-tools/pull/33
+    (fetchpatch {
+      url = "https://github.com/xiph/vorbis-tools/commit/8a645f78b45ae7e370c0dc2a52d0f2612aa6110b.patch";
+      hash = "sha256-RkT9Xa0pRu/oO9E9qhDa17L0luWgYHI2yINIkPZanmI=";
+    })
+  ];
 
-  env = lib.optionalAttrs stdenv.cc.isClang {
-    NIX_CFLAGS_COMPILE = "-Wno-error=implicit-function-declaration";
-  };
+  nativeBuildInputs = [ autoreconfHook pkg-config ];
+  buildInputs = [ libogg libvorbis libao curl speex flac ]
+    ++ lib.optionals stdenv.isDarwin [ libiconv ];
 
   meta = with lib; {
     description = "Extra tools for Ogg-Vorbis audio codec";