diff --git a/doc/Makefile b/doc/Makefile
index 5afd552..6f05775 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -14,10 +14,15 @@
 
 .PHONY: help Makefile
 
+watch:
+	sphinx-autobuild "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+dox: doxygen
+doxygen:
+	doxygen lisp.doxyfile
+	doxygen kernel.doxyfile
+
 # Catch-all target: route all unknown targets to Sphinx using the new
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %: Makefile
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
-
-watch:
-	sphinx-autobuild "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)