diff --git a/__init__.py b/__init__.py
index 039188c1..756e46e8 100644
--- a/__init__.py
+++ b/__init__.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-REVISION = '621'
+REVISION = None
 
 ### import all the goodies and add some helper functions for easy CLI use
 
@@ -11,7 +11,7 @@ from .Qt import QtGui
 #if QtGui.QApplication.instance() is None:
     #app = QtGui.QApplication([])
 
-import sys
+import os, sys
 
 ## check python version
 if sys.version_info[0] < 2 or (sys.version_info[0] == 2 and sys.version_info[1] != 7):
@@ -53,6 +53,13 @@ def systemInfo():
     print "sys.version:", sys.version
     from .Qt import VERSION_INFO
     print "qt bindings:", VERSION_INFO
+    
+    global REVISION
+    if REVISION is None:  ## this code was probably checked out from bzr; look up the last-revision file
+        lastRevFile = os.path.join(os.path.dirname(__file__), '.bzr', 'branch', 'last-revision')
+        if os.path.exists(lastRevFile):
+            REVISION = open(lastRevFile, 'r').read().strip()
+    
     print "pyqtgraph:", REVISION
     print "config:"
     import pprint