diff --git a/check_package/tasks.py b/check_package/tasks.py
index 680b51f..b1e9f5f 100644
--- a/check_package/tasks.py
+++ b/check_package/tasks.py
@@ -7,5 +7,5 @@ from invoke import task, run
 def setup_virtualenvs(ctx):
     temp_dir = tempfile.mkdtemp()
     run('virtualenv {}'.format(temp_dir))
-    run('./{}/bin/activate'.format(temp_dir))
-    run('pip install -e .')
+    run('{}/bin/pip install -e .'.format(temp_dir))
+    # TODO: Run tests after the installation.
diff --git a/pyproject.toml b/pyproject.toml
index a96b309..41cea70 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,4 +16,4 @@ virtualenv = "^16.0"
 pytest = "^3.0"
 
 [tool.poetry.scripts]
-check-package = 'check_package.main:program'
+'check-package' = 'check_package.main:program.run'