diff --git a/dlib/cmake_utils/add_python_module b/dlib/cmake_utils/add_python_module
index 2f0f191a7..25c267bad 100644
--- a/dlib/cmake_utils/add_python_module
+++ b/dlib/cmake_utils/add_python_module
@@ -52,6 +52,8 @@ set(Boost_NO_BOOST_CMAKE ON)
 if (NOT WIN32)
     set(BOOST_LIBRARYDIR ${BOOST_LIBRARYDIR} $ENV{BOOST_LIBRARYDIR}  
             /usr/lib/x86_64-linux-gnu/)
+else()
+    link_directories($ENV{BOOST_LIBRARYDIR})
 endif()
 if (PYTHON3)
     # On some systems the boost python3 module is called python-py34 so check