diff --git a/tools/update_revnum.py b/tools/update_revnum.py
new file mode 100755
index 0000000..eafc1b9
--- /dev/null
+++ b/tools/update_revnum.py
@@ -0,0 +1,13 @@
+""" Change the revision number in Release.py """
+
+import os
+import re
+
+rev = os.popen('svnversion').read().strip()
+
+print "current rev is",rev
+assert ':' not in rev
+
+rfile = open('../IPython/Release.py').read()
+newcont = re.sub(r'revision\s*=.*', "revision = '%s'" % rev, rfile)
+open('../IPython/Release.py','w').write(newcont)
\ No newline at end of file