diff --git a/ChangeLog b/ChangeLog
index d96a1a442..3497fd770 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2012-12-22  Moritz Bunkus  <moritz@bunkus.org>
+
+	* Build system: Boost's "variant" library is now required.
+
 2012-12-17  Moritz Bunkus  <moritz@bunkus.org>
 
 	* mkvmerge: bug fix: ISO 639-2 language handling: The deprecated
diff --git a/README b/README
index fed010b33..7e07139c3 100644
--- a/README
+++ b/README
@@ -80,7 +80,7 @@ programs and libraries you absolutely need are:
 
 - Boost ( http://www.boost.org/ ) -- Several of Boost's libraries are
   used: "format", "RegEx", "filesystem", "system", "foreach",
-  "Range", "rational". At least v1.46.0 is required.
+  "Range", "rational", "variant". At least v1.46.0 is required.
 
 You also need the "rake" or "drake" build program or at least the
 programming language Ruby and the "rubygems" package. MKVToolNix comes
diff --git a/ac/boost.m4 b/ac/boost.m4
index 04c5d64d3..ea928850b 100644
--- a/ac/boost.m4
+++ b/ac/boost.m4
@@ -41,3 +41,7 @@ AX_BOOST_CHECK_HEADERS([boost/type_traits/is_unsigned.hpp],,[
 AX_BOOST_CHECK_HEADERS([boost/range.hpp],,[
   AC_MSG_ERROR([Boost's Range library is required but wasn't found])
 ])
+
+AX_BOOST_CHECK_HEADERS([boost/variant.hpp],,[
+  AC_MSG_ERROR([Boost's variant library is required but wasn't found])
+])