diff --git a/pg_back.conf b/pg_back.conf
index 2898384..556ca9e 100644
--- a/pg_back.conf
+++ b/pg_back.conf
@@ -169,6 +169,8 @@ delete_uploaded = "no"
 # Google Cloud Storage (GCS) Access information. Bucket is mandatory. If the
 # path to the key file is empty, the GOOGLE_APPLICATION_CREDENTIALS environment
 # variable is used.
+# Note: when using a custom gcs_endpoint, do not specify https:// just use the
+# base API URL
 # gcs_bucket =
 # gcs_endpoint =
 # gcs_keyfile =