diff --git a/README.txt b/README.txt
index 50ee93034..7a8d872f0 100644
--- a/README.txt
+++ b/README.txt
@@ -143,6 +143,9 @@ GPL-compatible license.  Specifically:
   libmad: GPL
     Decodes MP3 files.  Optional separate download.
 
+  libmp3lame: LGPL
+    Encodes MP3 files.
+
   libnyquist: BSD-like license.
     Functional language for manipulating audio; available
     within Audacity for effects processing.