diff --git a/Makefile b/Makefile
index 5655479..74a3806 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,8 @@
 HTML2MARKDOWN=html2text
+GIT=git
+GITFLAGS=
 
-all: bin/tidy README.md
+all: bin/tidy README.md VERSION
 
 bin/tidy:
 	$(MAKE) -C build/gmake
@@ -8,6 +10,9 @@ bin/tidy:
 README.md: README.html
 	$(HTML2MARKDOWN) $(HTML2MARKDOWNFLAGS) $< > $@
 
+VERSION:
+	$(GIT) $(GITFLAGS) log --pretty=format:'https://github.com/w3c/tidy-html5/tree/%h' -n 1 > $@
+
 install:
 	sudo $(MAKE) install -C build/gmake
 
diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..3872684
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+https://github.com/w3c/tidy-html5/tree/35f2516