diff --git a/Makefile b/Makefile
index fa4cdcb..2e3ba0d 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ DATE		?= $(shell date --rfc-email)
 VERSION		?= $(shell git symbolic-ref --short HEAD 2>/dev/null)/$(shell git rev-list --count HEAD 2>/dev/null)/$(shell git rev-parse --short=8 HEAD 2>/dev/null)
 export DATE VERSION
 
-.PHONY: all checksums docs rsc clean
+.PHONY: all checksums commitinfo docs rsc clean
 
 all: checksums docs rsc
 
@@ -21,6 +21,10 @@ checksums: checksums.json
 checksums.json: contrib/checksums.sh $(ALL_RSC)
 	contrib/checksums.sh > $@
 
+commitinfo: global-functions.rsc
+	contrib/commitinfo.sh $< > $<~
+	mv $<~ $<
+
 docs: $(HTML)
 
 %.html: %.md general/style.css contrib/html.sh contrib/html.sh.d/head.html contrib/html.sh.d/foot.html
diff --git a/contrib/commitinfo.sh b/contrib/commitinfo.sh
new file mode 100755
index 0000000..21faf9f
--- /dev/null
+++ b/contrib/commitinfo.sh
@@ -0,0 +1,6 @@
+#!/bin/sh
+
+sed \
+	-e "/^:global CommitId/c :global CommitId \"${COMMITID:-unknown}\";" \
+	-e "/^:global CommitInfo/c :global CommitInfo \"${COMMITINFO:-unknown}\";" \
+	< "${1}"