diff --git a/src/allmydata/scripts/runner.py b/src/allmydata/scripts/runner.py
index eacff4fcd..1b6af812d 100644
--- a/src/allmydata/scripts/runner.py
+++ b/src/allmydata/scripts/runner.py
@@ -9,7 +9,8 @@ class Options(usage.Options):
     synopsis = "Usage:  allmydata <command> [command options]"
 
     optFlags = [
-        ["quiet", "q", "operate silently"],
+        ["quiet", "q", "Operate silently."],
+        ["version", "V", "Display version numbers and exit."],
         ]
 
     subCommands = []
@@ -18,6 +19,15 @@ class Options(usage.Options):
     subCommands += debug.subCommands
     subCommands += cli.subCommands
 
+    def opt_version(self):
+        from twisted import copyright
+        import allmydata, zfec, foolscap
+        print "Twisted version:", copyright.version
+        print "Foolscap version:", foolscap.__version__
+        print "zfec version:", zfec.__version__
+        print "allmydata version:", allmydata.__version__
+        sys.exit(0)
+
     def postOptions(self):
         if not hasattr(self, 'subOptions'):
             raise usage.UsageError("must specify a command")