diff --git a/mnpw/nagios.py b/mnpw/nagios.py
index a518d9b383e9c7a3fcbc2bd62e5610f3c05a5ac0..3bde99a65c961a5a923294a548960a149b2fd3c8 100644
--- a/mnpw/nagios.py
+++ b/mnpw/nagios.py
@@ -69,10 +69,11 @@ class Check:
                     self.Command,
                 ]
                 + self.Arguments,
-                capture_output=True,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
                 check=False,
-                text=True,
                 timeout=timeout,
+                universal_newlines=True,
             )
         except FileNotFoundError:
             raise RuntimeError(f"Command {self.Command} not found.")