diff --git a/tox.ini b/tox.ini
index 17301b9a0..d29b1ff56 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,7 @@ conda_deps =
     pytest
     pytest-cov
     pytest-xdist
+    coverage <=6.4.0
 
     # Package dependencies
     attrs