diff --git a/pyproject.toml b/pyproject.toml
index e7b1609d..93f037ba 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,7 +42,7 @@ dev = [
     "recommonmark",
     "sphinx_rtd_theme",
 ]
-test = ["playwright", "pytest", "pytest-playwright"]
+test = ["playwright", "pytest", "pytest-playwright", "pytest-cov"]
 
 [project.urls]
 repo = "https://github.com/materialsproject/crystaltoolkit"