diff --git a/ChangeLog b/ChangeLog
index dc3aa220e..aad224b52 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,8 @@
 
         * Released v7.8.0.
 
+        * build system: Boost's »Math« library is now required.
+
         * mkvmerge: bug fix: HEVC tracks which did not have an aspect
         ratio present in their sequence parameter set were copied
         incorrectly; the resulting sequence parameter set was
diff --git a/README.md b/README.md
index ceed98251..1cc6642d1 100644
--- a/README.md
+++ b/README.md
@@ -79,7 +79,7 @@ programs and libraries you absolutely need are:
 - zlib ( http://www.zlib.net/ ) -- a compression library
 
 - Boost ( http://www.boost.org/ ) -- Several of Boost's libraries are
-  used: "format", "RegEx", "filesystem", "system", "foreach",
+  used: "format", "RegEx", "filesystem", "system", "foreach", "math",
   "Range", "rational", "variant". At least v1.46.0 is required.
 
 You also need the `rake` or `drake` build program or at least the