diff --git a/requirements_dev.txt b/requirements_dev.txt
index c4c5d39..d6fc2f0 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,5 +1,5 @@
 pytest==6.1.2
-pytest-cov==2.10.1
+pytest-cov==4.0.0
 
 # Used in dev.py.
 executor>=21.0