diff --git a/requirements-test.txt b/requirements-test.txt
index 3c0aff2d..b6c9b2e4 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -4,3 +4,4 @@ contexttimer
 # QA checks
 openwisp-utils[qa]~=1.0.0
 packaging~=20.4
+importlib-metadata<5.0  # remove when flake8 is upgraded