diff --git a/docs/conf.py b/docs/conf.py
index 3a9c66c..18b647d 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -2,13 +2,12 @@
 #
 # This file is execfile()d with the current directory set to its containing dir.
 
-import os, sys, time, cgi
+import re, os, sys, time, cgi
 sys.path.append(os.path.abspath(".."))
 
 from get_version import __version__ as hy_version
-if hy_version.endswith(".dirty"):
-    # Read the Docs might dirty its checkout, so ignore this.
-    hy_version = hy_version[:-len(".dirty")]
+# Read the Docs might dirty its checkout, so strip the dirty flag.
+hy_version = re.sub('[+.]dirty\Z', '', hy_version)
 
 templates_path = ['_templates']
 source_suffix = '.rst'