diff --git a/tox.ini b/tox.ini
index e2d1f2fe90..e76a59c989 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,7 +33,9 @@ commands=
     integration-ethtester: pytest {posargs:tests/integration/test_ethereum_tester.py}
     docs: make check-docs-ci
 deps =
-    .[dev]
+    .[test]
+    ; install both `docs` and `test` dependencies for the `docs` environment
+    docs: .[docs]
 passenv =
     GETH_BINARY
     GOROOT