diff --git a/docs/User-Manual.md b/docs/User-Manual.md
index 9a2fde14..1bff3a9f 100644
--- a/docs/User-Manual.md
+++ b/docs/User-Manual.md
@@ -44,6 +44,8 @@ The following packages are required:
         wget http://concurrencykit.org/releases/ck-0.5.0.tar.gz
         tar xfz ck-0.5.0.tar.gz ; cd ck-0.5.0 ; ./configure && make all && sudo make install
         sudo ldconfig
+
+- [LibTomMath](https://github.com/libtom/libtommath) - Again, this library should be available via package manager, and that is the recommended installation method.
     
 # Installation