diff --git a/nix-system-configs/modules/system/gramethus.nix b/nix-system-configs/modules/system/gramethus.nix
index bd87eaa..05cbead 100644
--- a/nix-system-configs/modules/system/gramethus.nix
+++ b/nix-system-configs/modules/system/gramethus.nix
@@ -192,6 +192,8 @@ in {
         limits_config = {
           reject_old_samples = true;
           reject_old_samples_max_age = "168h";
+          # Disable structured metadata/OTLP native ingestion until schema is upgraded to v13+ and tsdb index is used.
+          allow_structured_metadata = false;
         };