diff --git a/setup.py b/setup.py
index 799d4699..bd0f8e50 100755
--- a/setup.py
+++ b/setup.py
@@ -142,7 +142,9 @@ def run(self):
             'six',
             'pytest-xdist',
             'virtualenv',
-        ]
+        ],
+        # Enable pyproject.toml support.
+        'toml': ['coverage[toml]'],
     },
     entry_points={
         'pytest11': [