diff --git a/src/libslic3r/GCode/ToolOrdering.hpp b/src/libslic3r/GCode/ToolOrdering.hpp
index f140a4f4773..d6d220d7a7d 100644
--- a/src/libslic3r/GCode/ToolOrdering.hpp
+++ b/src/libslic3r/GCode/ToolOrdering.hpp
@@ -143,6 +143,10 @@ public:
     unsigned int wall_extruder_id(const PrintRegion &region) const;
     unsigned int sparse_infill_filament_id(const PrintRegion &region) const;
     unsigned int internal_solid_filament_id(const PrintRegion &region) const;
+    // ImageMap aliases (1-based filament id)
+    unsigned int wall_filament(const PrintRegion &region) const;
+    unsigned int sparse_infill_filament(const PrintRegion &region) const;
+    unsigned int solid_infill_filament(const PrintRegion &region) const;
 	// Returns a zero based extruder this eec should be printed with, according to PrintRegion config or extruder_override if overriden.
 	unsigned int extruder(const ExtrusionEntityCollection &extrusions, const PrintRegion &region) const;
     unsigned int resolve_filament_id(unsigned int filament_id_1based) const;