diff --git a/Tools/msi/purge.py b/Tools/msi/purge.py
index a8b8f4d..27b6b05 100644
--- a/Tools/msi/purge.py
+++ b/Tools/msi/purge.py
@@ -12,7 +12,7 @@
 
 from urllib.request import *
 
-VERSION_RE = re.compile(r'(\d+\.\d+\.\d+)(\w+\d+)?$')
+VERSION_RE = re.compile(r'(\d+\.\d+\.\d+)([A-Za-z_]+\d+)?$')
 
 try:
     m = VERSION_RE.match(sys.argv[1])