diff --git a/tox.ini b/tox.ini
index 21f46435..afa838ab 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,7 @@ envlist =
 combine_as_imports=False
 force_sort_within_sections=True
 include_trailing_comma=True
-known_third_party=hypothesis,pytest,p2pclient,pexpect,factory
+known_third_party=hypothesis,pytest,p2pclient,pexpect,factory,lru
 known_first_party=libp2p
 line_length=88
 multi_line_output=3