diff --git a/app.py b/app.py
index 86d628a..d31ed40 100644
--- a/app.py
+++ b/app.py
@@ -110,18 +110,35 @@ def inject_globals():
 # ════════════════════════════════════════════════════════════════════
 #  BIND helpers
 # ════════════════════════════════════════════════════════════════════
+# python3.7
+#def run_cmd(cmd, timeout=10):
+#    """Run shell command, return (returncode, stdout, stderr)."""
+#    try:
+#        r = subprocess.run(cmd, shell=True, capture_output=True, text=True, timeout=timeout)
+#        return r.returncode, r.stdout.strip(), r.stderr.strip()
+#    except subprocess.TimeoutExpired:
+#        return -1, "", "Command timed out"
+#    except Exception as e:
+#        return -1, "", str(e)
 
+# python3.6
 def run_cmd(cmd, timeout=10):
     """Run shell command, return (returncode, stdout, stderr)."""
     try:
-        r = subprocess.run(cmd, shell=True, capture_output=True, text=True, timeout=timeout)
+        r = subprocess.run(
+            cmd,
+            shell=True,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            universal_newlines=True,
+            timeout=timeout
+        )
         return r.returncode, r.stdout.strip(), r.stderr.strip()
     except subprocess.TimeoutExpired:
         return -1, "", "Command timed out"
     except Exception as e:
         return -1, "", str(e)
 
-
 def bind_service_status():
     rc, out, _ = run_cmd("systemctl is-active named 2>&1")
     enabled_rc, _, _ = run_cmd("systemctl is-enabled named 2>&1")