--- a/hgext/purge.py
+++ b/hgext/purge.py
@@ -73,11 +73,15 @@
             ui.write('%s%s' % (name, eol))
 
     def removefile(path):
-        # read-only files cannot be unlinked under Windows
-        s = os.stat(path)
-        if (s.st_dev & stat.S_IWRITE) == 0:
-            os.chmod(path, s.st_mode | stat.S_IWRITE)
-        os.remove(path)
+        try:
+            os.remove(path)
+        except OSError:
+            # read-only files cannot be unlinked under Windows
+            s = os.stat(path)
+            if (s.st_mode & stat.S_IWRITE) != 0:
+                raise
+            os.chmod(path, stat.S_IMODE(s.st_mode) | stat.S_IWRITE)
+            os.remove(path)
 
     directories = []
     match = cmdutil.match(repo, dirs, opts)

--- a/tests/test-purge
+++ b/tests/test-purge
@@ -38,7 +38,7 @@
 python <<EOF
 import os, stat
 f= 'untracked_file_readonly'
-os.chmod(f, os.stat(f).st_mode & ~stat.S_IWRITE)
+os.chmod(f, stat.S_IMODE(os.stat(f).st_mode) & ~stat.S_IWRITE)
 EOF
 hg purge -p
 hg purge -v