diff --git a/src/libslic3r/Technologies.hpp b/src/libslic3r/Technologies.hpp
index 7a6a682b1..3a87439c2 100644
--- a/src/libslic3r/Technologies.hpp
+++ b/src/libslic3r/Technologies.hpp
@@ -38,6 +38,8 @@
 #define ENABLE_2_2_0_ALPHA1 1
 
 // Enable thumbnail generator
+// When removing this technology, remove it also from stable branch, 
+// where it has been partially copied for patch 2.1.1
 #define ENABLE_THUMBNAIL_GENERATOR (1 && ENABLE_2_2_0_ALPHA1)
 #define ENABLE_THUMBNAIL_GENERATOR_DEBUG (0 && ENABLE_THUMBNAIL_GENERATOR)
 
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index a74c6b0c0..891582dbb 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -51,10 +51,10 @@
 #include <Shlobj.h>
 #endif // __WXMSW__
 
-#if ENABLE_THUMBNAIL_GENERATOR
+#if ENABLE_THUMBNAIL_GENERATOR_DEBUG
 #include <boost/beast/core/detail/base64.hpp>
 #include <boost/nowide/fstream.hpp>
-#endif // ENABLE_THUMBNAIL_GENERATOR
+#endif // ENABLE_THUMBNAIL_GENERATOR_DEBUG
 
 namespace Slic3r {
 namespace GUI {
diff --git a/src/slic3r/GUI/GUI_App.hpp b/src/slic3r/GUI/GUI_App.hpp
index bc912086e..a730ff95f 100644
--- a/src/slic3r/GUI/GUI_App.hpp
+++ b/src/slic3r/GUI/GUI_App.hpp
@@ -188,10 +188,10 @@ public:
     void            open_web_page_localized(const std::string &http_address);
     bool            run_wizard(ConfigWizard::RunReason reason, ConfigWizard::StartPage start_page = ConfigWizard::SP_WELCOME);
 
-#if ENABLE_THUMBNAIL_GENERATOR
+#if ENABLE_THUMBNAIL_GENERATOR_DEBUG
     // temporary and debug only -> extract thumbnails from selected gcode and save them as png files
     void            gcode_thumbnails_debug();
-#endif // ENABLE_THUMBNAIL_GENERATOR
+#endif // ENABLE_THUMBNAIL_GENERATOR_DEBUG
 
 private:
     bool            on_init_inner();