diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,9 @@
 # Add here external Python modules dependencies, one per line. Module names
 # should match https://pypi.python.org/pypi names. For the full spec or
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
+click
 iso8601
 methodtools
+PyYAML
+types-click
+types-PyYAML
diff --git a/swh/__init__.py b/swh/__init__.py
--- a/swh/__init__.py
+++ b/swh/__init__.py
@@ -1,4 +1,4 @@
 from pkgutil import extend_path
-from typing import Iterable
+from typing import List
 
-__path__: Iterable[str] = extend_path(__path__, __name__)
+__path__: List[str] = extend_path(__path__, __name__)