diff --git a/Tools/msi/msi.py b/Tools/msi/msi.py
index 2d88e42..4f750e6 100644
--- a/Tools/msi/msi.py
+++ b/Tools/msi/msi.py
@@ -116,6 +116,8 @@
 
 # Compute the name that Sphinx gives to the docfile
 docfile = ""
+if micro:
+    docfile = str(micro)
 if level < 0xf:
     docfile = '%x%s' % (level, serial)
 docfile = 'python%s%s%s.chm' % (major, minor, docfile)