diff --git a/mitmproxy/test/tutils.py b/mitmproxy/test/tutils.py
index 5b2bfe353..79751060e 100644
--- a/mitmproxy/test/tutils.py
+++ b/mitmproxy/test/tutils.py
@@ -46,7 +46,7 @@ def tresp(**kwargs) -> http.Response:
         reason=b"OK",
         headers=http.Headers(((b"header-response", b"svalue"), (b"content-length", b"7"))),
         content=b"message",
-        trailers=http.Headers(((b"trailer-response", b"svalue"), (b"trailer", b"this trailer-1"))),
+        trailers=None,
         timestamp_start=946681202,
         timestamp_end=946681203,
     )
diff --git a/test/mitmproxy/addons/test_dumper.py b/test/mitmproxy/addons/test_dumper.py
index d0d9d4e9b..aeed8b114 100644
--- a/test/mitmproxy/addons/test_dumper.py
+++ b/test/mitmproxy/addons/test_dumper.py
@@ -6,6 +6,7 @@ import pytest
 
 from mitmproxy import exceptions
 from mitmproxy.addons import dumper
+from mitmproxy.net.http import Headers
 from mitmproxy.test import taddons
 from mitmproxy.test import tflow
 from mitmproxy.test import tutils
@@ -128,15 +129,17 @@ def test_echo_body():
 
         f = tflow.tflow(client_conn=True, server_conn=True, resp=True)
         f.response.headers["content-type"] = "text/html"
+        f.response.headers["transfer-encoding"] = "chunked"
+        f.response.headers["trailer"] = "my-little-trailer"
         f.response.content = b"foo bar voing\n" * 100
-        f.response.trailers["trailer-2"] = "this is trailer 2"
+        f.response.trailers = Headers([(b"my-little-trailer", b"foobar-trailer")])
         d._echo_headers(f.response.headers)
         d._echo_message(f.response, f)
         d._echo_headers(f.response.trailers)
         t = sio.getvalue()
         assert "content-type" in t
         assert "cut off" in t
-        assert "trailer-2" in t
+        assert "foobar-trailer" in t
 
 
 def test_echo_request_line():
diff --git a/test/mitmproxy/net/http/http1/test_assemble.py b/test/mitmproxy/net/http/http1/test_assemble.py
index 4fea192fc..ab3dac04c 100644
--- a/test/mitmproxy/net/http/http1/test_assemble.py
+++ b/test/mitmproxy/net/http/http1/test_assemble.py
@@ -40,6 +40,22 @@ def test_assemble_response():
         b"message"
     )
 
+    resp = tresp()
+    resp.headers["transfer-encoding"] = "chunked"
+    resp.headers["trailer"] = "my-little-trailer"
+    resp.trailers = Headers([(b"my-little-trailer", b"foobar")])
+    assert assemble_response(resp) == (
+        b"HTTP/1.1 200 OK\r\n"
+        b"header-response: svalue\r\n"
+        b"content-length: 7\r\n"
+        b"transfer-encoding: chunked\r\n"
+        b"trailer: my-little-trailer\r\n"
+        b"\r\n7\r\n"
+        b"message"
+        b"\r\n0\r\n"
+        b"my-little-trailer: foobar\r\n\r\n"
+    )
+
     with pytest.raises(exceptions.HttpException):
         assemble_response(tresp(content=None))