diff --git a/backend/src/api/nft_manager.py b/backend/src/api/nft_manager.py
index e0cd803..8633bda 100644
--- a/backend/src/api/nft_manager.py
+++ b/backend/src/api/nft_manager.py
@@ -61,24 +61,10 @@ class NftManager:
         Try to obtain nft -j list ruleset (JSON). Returns parsed JSON dict on success.
         Raises NftError on failure or when output cannot be parsed as JSON.
         """
-        cmd_variants = ["list ruleset -j", "list ruleset"]
-        last_err = None
-        for c in cmd_variants:
-            res = self.cmd(c)
-            if res["rc"] != 0:
-                last_err = res["stderr"]
-                continue
-            out = res["stdout"]
-            if not out:
-                last_err = "empty output"
-                continue
-            try:
-                parsed = json.loads(out)
-                return parsed
-            except json.JSONDecodeError as e:
-                last_err = f"json decode error: {e}"
-                continue
-        raise NftError(f"unable to get JSON ruleset: {last_err}")
+        res = self.nft.json_cmd("list ruleset")
+        if res["rc"] != 0:
+            raise NftError(f"nft list ruleset failed: {res['stderr']}")
+        return res["stdout"]
 
     def list_chain_text(self, family: str, table: str, chain: str) -> str:
         """