diff --git a/Doc/tools/sphinx-build.py b/Doc/tools/sphinx-build.py
index e19b10a..8f952be 100644
--- a/Doc/tools/sphinx-build.py
+++ b/Doc/tools/sphinx-build.py
@@ -11,9 +11,9 @@
 
 if __name__ == '__main__':
 
-    if sys.version_info[:3] < (2, 5, 0):
+    if sys.version_info[:3] < (2, 5, 1):
         print >>sys.stderr, """\
-Error: Sphinx needs to be executed with Python 2.5 or newer
+Error: Sphinx needs to be executed with Python 2.5.1 or newer
 (If you run this from the Makefile, you can set the PYTHON variable
 to the path of an alternative interpreter executable, e.g.,
 ``make html PYTHON=python2.5``).