diff --git a/src/slic3r/Utils/OctoPrint.cpp b/src/slic3r/Utils/OctoPrint.cpp
index 11c7d243c9..f926a97656 100644
--- a/src/slic3r/Utils/OctoPrint.cpp
+++ b/src/slic3r/Utils/OctoPrint.cpp
@@ -17,6 +17,7 @@
 #include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/I18N.hpp"
 #include "slic3r/GUI/GUI.hpp"
+#include "slic3r/GUI/format.hpp"
 #include "Http.hpp"
 #include "libslic3r/AppConfig.hpp"