diff --git a/pyinfra/storage/adapters/s3.py b/pyinfra/storage/adapters/s3.py
index 46b5c2b..dab3ec8 100644
--- a/pyinfra/storage/adapters/s3.py
+++ b/pyinfra/storage/adapters/s3.py
@@ -65,6 +65,8 @@ def _parse_endpoint(endpoint):
     if url(endpoint):
         parsed_url = urlparse(endpoint)
         return {"secure": parsed_url.scheme == "https", "endpoint": parsed_url.netloc}
+    else:
+        raise f"The configured storage endpoint is not a valid url: {endpoint}"
 
 
 def get_s3_storage(config: Config):