diff --git a/pyproject.toml b/pyproject.toml
index 95426521..bb470400 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,8 +44,11 @@ fakeredis = "*"
 mypy = "*"
 types-redis = "*"
 
+# for dev, extra is installed by default
+[tool.poetry.group.dev-gcs]
+[tool.poetry.group.dev-gcs.dependencies]
+google-api-python-client = "*"
 [tool.poetry.group.dev-s3]
-optional = true
 [tool.poetry.group.dev-s3.dependencies]
 moto = "*"
 
diff --git a/tox.ini b/tox.ini
index 1597e187..e27251e6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,12 +6,13 @@ isolated_build = true
 allowlist_externals = poetry, pytest
 skip_install = true
 commands =
-    s3: poetry install -E s3 --with=dev-s3
+    s3: poetry install -E s3 --without=dev-gcs
     s3: pytest -v -m "s3"
 
-    gcs: poetry install -E gcs
+    gcs: poetry install -E gcs --without=dev-gcs
     gcs: pytest -v -m "gcs"
 
+    core: poetry install --without=dev-s3 --without=dev-gcs
     core: pytest -v -m "not gcs and not s3"
 
 [testenv:yapf]