diff --git a/cibuildwheel/__main__.py b/cibuildwheel/__main__.py
index 9e4e57ae..87d74b30 100644
--- a/cibuildwheel/__main__.py
+++ b/cibuildwheel/__main__.py
@@ -310,14 +310,10 @@ def detect_warnings(platform: str, build_options: BuildOptions) -> List[str]:
 
 
 def detect_setup_pyproject_existence(package_dir: str) -> bool:
-    exists = False
-    if os.path.exists(os.path.join(package_dir, 'setup.py')):
-        exists = True
-
-    if os.path.exists(os.path.join(package_dir, 'pyproject.toml')):
-        exists = True
-
-    return exists
+    return any(
+        os.path.exists(os.path.join(package_dir, name))
+        for name in ["setup.py", "setup.cfg", "pyproject.toml"]
+    )
 
 
 if __name__ == '__main__':