diff --git a/action.yml b/action.yml
index 4389c5e..9b66928 100644
--- a/action.yml
+++ b/action.yml
@@ -69,10 +69,10 @@ runs:
 
     - name: Check for invalid package versions in pyproject.toml
       run: |
-        poetry install --directory ${{ github.action_path }}
-        poetry run --directory ${{ github.action_path }} invalid_package_versions
+        poetry install
+        poetry run invalid_package_versions ${{ inputs.working_directory }}/pyproject.toml
       shell: bash
-      working-directory: ${{ github.workspace }}
+      working-directory: ${{ github.action_path }}
 
     - name: Create virtualenv and install dependencies
       shell: bash
diff --git a/action_setup_python_poetry/invalid_package_versions.py b/action_setup_python_poetry/invalid_package_versions.py
index bf8868a..d43393c 100644
--- a/action_setup_python_poetry/invalid_package_versions.py
+++ b/action_setup_python_poetry/invalid_package_versions.py
@@ -30,7 +30,8 @@ def get_invalid_package_versions(pyproject_toml_file_text: str) -> Sequence[tupl
 
 
 def main():
-    if invalid_versions := get_invalid_package_versions(Path("pyproject.toml").read_text()):
+    pyproject_path = Path(sys.argv[1] if len(sys.argv) > 1 else "pyproject.toml")
+    if invalid_versions := get_invalid_package_versions(pyproject_path.read_text()):
         print(f"Invalid package versions found in pyproject.toml: {invalid_versions}")
         sys.exit(1)