diff --git a/pkgs/applications/video/MPlayer/default.nix b/pkgs/applications/video/MPlayer/default.nix
index c3118cbf482..b0456d79146 100644
--- a/pkgs/applications/video/MPlayer/default.nix
+++ b/pkgs/applications/video/MPlayer/default.nix
@@ -1,8 +1,10 @@
-{ alsaSupport ? false, xvSupport ? true
-, stdenv, fetchurl, x11, libXv, freetype, zlib, alsa ? null}:
+{ alsaSupport ? false, xvSupport ? true, theoraSupport ? false
+, stdenv, fetchurl, x11, freetype, zlib
+, alsa ? null, libXv ? null, libtheora ? null}:
 
 assert alsaSupport -> alsa != null;
 assert xvSupport -> libXv != null;
+assert theoraSupport -> libtheora != null;
 
 stdenv.mkDerivation {
   name = "MPlayer-1.0pre6";
@@ -25,5 +27,6 @@ stdenv.mkDerivation {
     x11 libXv freetype zlib
     (if alsaSupport then alsa else null)
     (if xvSupport then libXv else null)
+    (if theoraSupport then libtheora else null)
   ];
 }
diff --git a/pkgs/development/libraries/libtheora/default.nix b/pkgs/development/libraries/libtheora/default.nix
new file mode 100644
index 00000000000..87e75e55da7
--- /dev/null
+++ b/pkgs/development/libraries/libtheora/default.nix
@@ -0,0 +1,10 @@
+{stdenv, fetchurl, libogg, libvorbis}:
+
+stdenv.mkDerivation {
+  name = "libtheora-1.0alpha4";
+  src = fetchurl {
+    url = http://downloads.xiph.org/releases/theora/libtheora-1.0alpha4.tar.bz2;
+    md5 = "a71ac42ec0f848da327930841a80ff2b";
+  };
+  propagatedBuildInputs = [libogg libvorbis];
+}
diff --git a/pkgs/development/libraries/libvorbis/default.nix b/pkgs/development/libraries/libvorbis/default.nix
index 1cb26577162..6a2385fe950 100644
--- a/pkgs/development/libraries/libvorbis/default.nix
+++ b/pkgs/development/libraries/libvorbis/default.nix
@@ -4,8 +4,7 @@ stdenv.mkDerivation {
   name = "libvorbis-1.1.0";
   src = fetchurl {
     url = http://catamaran.labs.cs.uu.nl/dist/tarballs/libvorbis-1.1.0.tar.gz;
-    md5 = "bb764aeabde613d1a424a29b1f15e7e6" ;
+    md5 = "bb764aeabde613d1a424a29b1f15e7e6";
   };
-
-   buildInputs = [libogg];
+  buildInputs = [libogg];
 }
diff --git a/pkgs/system/all-packages-generic.nix b/pkgs/system/all-packages-generic.nix
index 10eefe030d6..7e92044d662 100644
--- a/pkgs/system/all-packages-generic.nix
+++ b/pkgs/system/all-packages-generic.nix
@@ -547,6 +547,10 @@ rec {
     inherit fetchurl stdenv libogg;
   };
 
+  libtheora = (import ../development/libraries/libtheora) {
+    inherit fetchurl stdenv libogg libvorbis;
+  };
+
   libxml2 = (import ../development/libraries/libxml2) {
     inherit fetchurl stdenv zlib python;
   };
@@ -983,10 +987,11 @@ rec {
   };
 
   MPlayer = (import ../applications/video/MPlayer) {
-    inherit fetchurl stdenv freetype x11 zlib;
+    inherit fetchurl stdenv freetype x11 zlib libtheora;
     inherit (xlibs) libXv;
     alsaSupport = true;
     alsa = alsaLib;
+    theoraSupport = true;
   };
 
   MPlayerPlugin = (import ../applications/networking/browsers/mozilla-plugins/mplayerplug-in) {