diff --git a/src/libslic3r/TriangleMeshSlicer.cpp b/src/libslic3r/TriangleMeshSlicer.cpp
index ea9eb5ff2..a3123ea76 100644
--- a/src/libslic3r/TriangleMeshSlicer.cpp
+++ b/src/libslic3r/TriangleMeshSlicer.cpp
@@ -23,6 +23,8 @@
 #endif
 
 #include <assert.h>
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/lock_guard.hpp>
 
 #if defined(SLIC3R_DEBUG) || defined(SLIC3R_DEBUG_SLICE_PROCESSING)
 #include "SVG.hpp"