--- a/Makefile
+++ b/Makefile
@@ -251,7 +251,7 @@
 	@git log --pretty=format:'%aN        %aE' | LC_ALL=C sort -u | awk -F'\t' '{printf("\t%s <%s>\n",$$1,$$2)}';
 
 doc: all
-	$(OCAMLBUILD) -package unix scripts/pack.native
+	$(OCAMLBUILD) -package unix scripts/pack.$(OCAMLEXT)
 	scripts/doc.sh $(OCAMLEXT)
 	#dot -Grotate=0 -Tsvg -o dose3.docdir/index.svg dose3.docdir/index.dot
 	(cd doc && $(MAKE) all)
