diff --git a/.gitignore b/.gitignore
index 462cc79..725ef0c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -140,3 +140,6 @@ cython_debug/
 # Generated version file
 actions_includes/version.py
 docker/*.tar.gz
+
+# Git worktrees
+.worktrees/
diff --git a/setup.py b/setup.py
index 974de65..b6a0e2e 100644
--- a/setup.py
+++ b/setup.py
@@ -70,7 +70,7 @@ def clean_scheme(version):
     # Requirements
     python_requires='>=3.8', # Needs ordered dictionaries
     install_requires = [
-        "ruamel.yaml",
+        "ruamel.yaml<0.18",  # TODO: Update code to support ruamel.yaml 0.18+ API (see issue #50)
     ],
     setup_requires = [
         "setuptools>=42",