diff --git a/modules/doc/install.rst b/modules/doc/install.rst
index f91152e4183226097713b5617038850a5c6fff28..585dafe3cfd87a45afcd88c6cccec4213a83a125 100644
--- a/modules/doc/install.rst
+++ b/modules/doc/install.rst
@@ -151,7 +151,7 @@ can influence it.
 * Boost is mainly controlled via the `BOOST_ROOT` option. If boost wasn't
   found, it should be set to the prefix of the boost installation. If for some
   reason, it is desirable to use the non-multithreaded boost libraries, you can
-  switch `Boost_USE_MULTITHREADED` on (it is off by default).
+  switch `Boost_USE_MULTITHREADED` off (it is on by default).
 
 * `PYTHON_ROOT` is the Python equivalent of BOOST_ROOT. It should be set to 
   the prefix path containing the python binary, headers and libraries.
diff --git a/modules/seq/alg/src/subst_weight_matrix.cc b/modules/seq/alg/src/subst_weight_matrix.cc
index d8102aa230cf7e4acb738f716e823e8ebb4ab884..315b00f10f9069ecaf08c8fde8afd684eb3dfea7 100644
--- a/modules/seq/alg/src/subst_weight_matrix.cc
+++ b/modules/seq/alg/src/subst_weight_matrix.cc
@@ -18,6 +18,7 @@
 //------------------------------------------------------------------------------
 
 #include "subst_weight_matrix.hh"
+#include <ost/base.hh>
 #include <iostream>
 
 namespace{