diff --git a/SConstruct b/SConstruct
index 31807d71b..8efe726ac 100644
--- a/SConstruct
+++ b/SConstruct
@@ -767,16 +767,20 @@ def FindBoost(context, prefixes, thread_flag):
     if BOOST_LIB_DIR:
         msg += '\nFound boost libs: %s' % BOOST_LIB_DIR
         env['BOOST_LIBS'] = BOOST_LIB_DIR
-    else:
+    elif not env['BOOST_LIBS']:
         env['BOOST_LIBS'] = '/usr/' + env['LIBDIR_SCHEMA']
         msg += '\nUsing default boost lib dir: %s' % env['BOOST_LIBS']
+    else:
+        msg += '\nUsing boost lib dir: %s' % env['BOOST_LIBS']
 
     if BOOST_INCLUDE_DIR:
         msg += '\nFound boost headers: %s' % BOOST_INCLUDE_DIR
         env['BOOST_INCLUDES'] = BOOST_INCLUDE_DIR
-    else:
+    elif not env['BOOST_INCLUDES']:
         env['BOOST_INCLUDES'] = '/usr/include'
         msg += '\nUsing default boost include dir: %s' % env['BOOST_INCLUDES']
+    else:
+        msg += '\nUsing boost include dir: %s' % env['BOOST_INCLUDES']
 
     if not env['BOOST_TOOLKIT'] and not env['BOOST_ABI'] and not env['BOOST_VERSION']:
         if BOOST_APPEND: