diff --git a/pyproject.toml b/pyproject.toml
index 9ee3c37a..00847375 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,6 +47,7 @@ dev = [
     "pytest",
     "pytest-cov",
     "ruff~=0.5.2",
+    "types-PyYAML",
     "sphinx-autobuild",
 ]
 
diff --git a/src/r2x/cli_functions.py b/src/r2x/cli_functions.py
index 2b6806cc..acdfd3c0 100644
--- a/src/r2x/cli_functions.py
+++ b/src/r2x/cli_functions.py
@@ -13,7 +13,7 @@ class Flags(argparse.Action):
     argparse
     """
 
-    def __call__(
+    def __call__(  # type: ignore
         self,
         parser: argparse.ArgumentParser,
         namespace: argparse.Namespace,