diff --git a/Makefile b/Makefile
index e8c4e50..5e9979e 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,7 @@ PREFIX=takeup
 OPENSCAD=openscad
 OPENSCAD_OPTIONS=-D VERBOSE=false
 OPENSCAD_IMAGE_OPTIONS=--imgsize=1024,1024 --colorscheme=DeepOcean --render
+C14N=python common/c14n_stl.py
 
 STL=./stl
 IMG=./img
@@ -52,4 +53,5 @@ cleanall:
 
 $(MODELS) : $(STL)/$(PREFIX)_%.stl : $(PREFIX).scad
 	$(OPENSCAD) $(OPENSCAD_OPTIONS) -o $@ -D PART=\"$(subst $(PREFIX)_,,$(subst .stl,,$(@F)))\" $<
+	$(C14N) $@ 
 	$(OPENSCAD) $(OPENSCAD_OPTIONS) $(OPENSCAD_IMAGE_OPTIONS) -o $(IMG)/$(subst $(STL),$(IMG)},$(subst .stl,.png,$(@F))) -D PART=\"$(subst $(PREFIX)_,,$(subst .stl,,$(@F)))\" $<