diff --git a/src/App/PropertyExpressionEngine.cpp b/src/App/PropertyExpressionEngine.cpp
index cf7a143ffa..cf6996d530 100644
--- a/src/App/PropertyExpressionEngine.cpp
+++ b/src/App/PropertyExpressionEngine.cpp
@@ -42,6 +42,7 @@ FC_LOG_LEVEL_INIT("App",true);
 using namespace App;
 using namespace Base;
 using namespace boost;
+using namespace boost::placeholders;
 
 TYPESYSTEM_SOURCE_ABSTRACT(App::PropertyExpressionContainer , App::PropertyXLinkContainer)