diff --git a/pyproject.toml b/pyproject.toml
index 3eb7571..d93f5bb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,7 +36,7 @@ Homepage = "https://githib.com/dave-shawley/tornado-problem-details"
 [tool.hatch.envs.default]
 python = "python3.12"
 dependencies = [
-    "coverage",
+    "coverage[toml]",
     "flake8",
     "flake8-fixme",
     "flake8-print",