diff --git a/tests/modcheck.py b/tests/modcheck.py
--- a/tests/modcheck.py
+++ b/tests/modcheck.py
@@ -17,7 +17,7 @@
 dirname = os.path.dirname
 
 # skip checking external modules
-skipmodre = re.compile(r'\Amysql|remotenames|hgsubversion.*\Z')
+skipmodre = re.compile(r'\Amysql|remotenames|hgsubversion.*|lz4revlog\Z')
 
 reporoot = dirname(dirname(__file__))
 pyroot = dirname(os.__file__)