diff --git a/librb/Makefile.am b/librb/Makefile.am
index c8cb6fc2..245174b8 100644
--- a/librb/Makefile.am
+++ b/librb/Makefile.am
@@ -4,3 +4,15 @@ SUBDIRS = src
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = librb.pc
+
+BUILT_SOURCES = include/serno.h
+
+include/serno.h:
+	@if [ -d .git ] ; then \
+		revh=`git log -1 --date=short --pretty=format:%cd_%h 2>/dev/null | sed -e s/-//g -e s/_/-/`;\
+		[ -z "$$revh" ] || echo '#define SERNO "'$$revh'"' >include/serno.h ; \
+	elif [ -d .hg ] ; then \
+		revh=`hg parents --template '{date|shortdate}_{node|short}' 2>/dev/null | sed -e s/-//g -e s/_/-/`;\
+		[ -z "$$revh" ] || echo '#define SERNO "'$$revh'"' >include/serno.h ; \
+	fi
+	@[ -f include/serno.h ] || echo '#define SERNO "unknown"' >include/serno.h
diff --git a/librb/configure.ac b/librb/configure.ac
index 511ab467..a76488a1 100644
--- a/librb/configure.ac
+++ b/librb/configure.ac
@@ -1,4 +1,3 @@
-dnl $Id: configure.ac 26260 2008-12-10 04:08:39Z androsyn $
 dnl Process this file with autoconf to produce a configure script.
 
 dnl TODO: clean up all the OpenSSL and shared module checking stuff;
@@ -8,7 +7,6 @@ dnl said functions need to be just about as complex as they already are.
 AC_PREREQ(2.63)
 AUTOMAKE_OPTIONS = 1.10
 dnl Sneaky way to get an Id tag into the configure script
-AC_COPYRIGHT([$Id: configure.ac 26260 2008-12-10 04:08:39Z androsyn $])
 AC_INIT([librb],[devel])
 AM_INIT_AUTOMAKE([subdir-objects])
 AM_SILENT_RULES([yes])