diff --git a/internal/deploy/deploy.go b/internal/deploy/deploy.go
index e62ae9f..a98d70c 100644
--- a/internal/deploy/deploy.go
+++ b/internal/deploy/deploy.go
@@ -107,6 +107,7 @@ func RunNewDeployment(t *testing.T, shouldTCPDump bool) *SlidingSyncDeployment {
 			Env:          map[string]string{},
 			Cmd: []string{
 				"mitmdump", "--mode", "reverse:http://hs1:8008@3000", "--mode", "reverse:http://hs2:8008@3001", "-s", "/addons/__init__.py",
+				//"--set", "statuscode=400",
 			},
 			// WaitingFor: wait.ForLog("listening"),
 			Networks: []string{networkName},
diff --git a/tests/addons/__init__.py b/tests/addons/__init__.py
index feb1d2e..efc8c06 100644
--- a/tests/addons/__init__.py
+++ b/tests/addons/__init__.py
@@ -1,4 +1,4 @@
-from add_header import AddHeader
+from status_code import StatusCode
 
 
-addons = [AddHeader()]
+addons = [StatusCode()]
diff --git a/tests/addons/add_header.py b/tests/addons/add_header.py
deleted file mode 100644
index 13c792f..0000000
--- a/tests/addons/add_header.py
+++ /dev/null
@@ -1,9 +0,0 @@
-class AddHeader:
-    def __init__(self):
-        self.num = 0
-
-    def response(self, flow):
-        self.num = self.num + 1
-        print("got response num", self.num)
-        flow.response.headers["count"] = str(self.num)
-        
\ No newline at end of file
diff --git a/tests/addons/status_code.py b/tests/addons/status_code.py
new file mode 100644
index 0000000..955cc5b
--- /dev/null
+++ b/tests/addons/status_code.py
@@ -0,0 +1,31 @@
+import logging
+
+from mitmproxy import ctx
+from mitmproxy.http import Response
+
+class StatusCode:
+    def __init__(self):
+        self.return_status_code = 0 # disabled
+
+    def load(self, loader):
+        loader.add_option(
+            name="statuscode",
+            typespec=int,
+            default=0,
+            help="Change the response status code",
+        )
+
+    def configure(self, updates):
+        if "statuscode" not in updates:
+            self.return_status_code = 0
+            return
+        if ctx.options.statuscode is None or ctx.options.statuscode == 0:
+            self.return_status_code = 0
+            return
+        self.return_status_code = ctx.options.statuscode
+        logging.info(f"statuscode will return HTTP {self.return_status_code}")
+
+    def response(self, flow):
+        if self.return_status_code == 0:
+            return
+        flow.response = Response.make(self.return_status_code)