diff --git a/tests/gateway/test_status.py b/tests/gateway/test_status.py
index c39285b75344..2866379041e8 100644
--- a/tests/gateway/test_status.py
+++ b/tests/gateway/test_status.py
@@ -723,7 +723,7 @@ class TestTerminatePid:
         calls = []
         monkeypatch.setattr(status, "_IS_WINDOWS", True)
 
-        def fake_run(cmd, capture_output=False, text=False, timeout=None, creationflags=0):
+        def fake_run(cmd, capture_output=False, text=False, timeout=None, creationflags=0, **kwargs):
             calls.append((cmd, capture_output, text, timeout, creationflags))
             return SimpleNamespace(returncode=0, stdout="", stderr="")
 
diff --git a/tests/gateway/test_webhook_integration.py b/tests/gateway/test_webhook_integration.py
index 9312ac0e999f..dea960bba1d7 100644
--- a/tests/gateway/test_webhook_integration.py
+++ b/tests/gateway/test_webhook_integration.py
@@ -331,6 +331,8 @@ class TestGitHubCommentDelivery:
             ],
             capture_output=True,
             text=True,
+            encoding="utf-8",
+            errors="replace",
             timeout=30,
         )
         # Delivery info is retained after send() so interim status messages
diff --git a/tests/gateway/test_whatsapp_connect.py b/tests/gateway/test_whatsapp_connect.py
index 52e36f5b7c2c..374ed74b8a7c 100644
--- a/tests/gateway/test_whatsapp_connect.py
+++ b/tests/gateway/test_whatsapp_connect.py
@@ -591,6 +591,8 @@ class TestHttpSessionLifecycle:
             ["taskkill", "/PID", "12345", "/T"],
             capture_output=True,
             text=True,
+            encoding="utf-8",
+            errors="replace",
             timeout=10,
         )
         mock_proc.terminate.assert_not_called()