diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 80fa14bb..a2ce1761 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -11,7 +11,7 @@ repos:
     -   id: name-tests-test
     -   id: requirements-txt-fixer
     -   id: double-quote-string-fixer
--   repo: https://gitlab.com/pycqa/flake8
+-   repo: https://gitlab.com/pycqa/flake8.git
     rev: 3.8.4
     hooks:
     -   id: flake8
diff --git a/pre_commit/languages/python.py b/pre_commit/languages/python.py
index 65f521cd..da528150 100644
--- a/pre_commit/languages/python.py
+++ b/pre_commit/languages/python.py
@@ -197,10 +197,17 @@ def install_environment(
     if python is not None:
         venv_cmd.extend(('-p', python))
     install_cmd = ('python', '-mpip', 'install', '.', *additional_dependencies)
+    setup_dependencies_env = os.environ.get('PYTHON_SETUP_DEPENDENCIES')
+    if setup_dependencies_env:
+        setup_dependencies = setup_dependencies_env.split(':')
+    else:
+        setup_dependencies = []
 
     with clean_path_on_failure(envdir):
         cmd_output_b(*venv_cmd, cwd='/')
         with in_env(prefix, version):
+            for dep in setup_dependencies:
+                cmd_output_b('python', '-mpip', 'install', dep)
             helpers.run_setup_cmd(prefix, install_cmd)