diff --git a/src/libslic3r/Flow.cpp b/src/libslic3r/Flow.cpp
index 97b3c1427..b7edb0f55 100644
--- a/src/libslic3r/Flow.cpp
+++ b/src/libslic3r/Flow.cpp
@@ -5,6 +5,7 @@
 #include <assert.h>
 
 #include <boost/algorithm/string/predicate.hpp>
+#include <boost/log/trivial.hpp>
 
 // Mark string for localization and translate.
 #define L(s) Slic3r::I18N::translate(s)