diff --git a/tests/test_page_inputs.py b/tests/test_page_inputs.py
index 038cb285..2621d2c0 100644
--- a/tests/test_page_inputs.py
+++ b/tests/test_page_inputs.py
@@ -262,7 +262,7 @@ def test_http_response_json():
     response = HttpResponse(url, body=b'{"key": "value"}')
     assert response.json() == {"key": "value"}
 
-    response = HttpResponse(url, '{"ключ": "значение"}'.encode("utf8"))
+    response = HttpResponse(url, body='{"ключ": "значение"}'.encode("utf8"))
     assert response.json() == {"ключ": "значение"}
 
 
@@ -274,7 +274,7 @@ def test_http_response_text():
     """
     text = "œ is a Weird Character"
     body = HttpResponseBody(b"\x9c is a Weird Character")
-    response = HttpResponse("http://example.com", body)
+    response = HttpResponse("http://example.com", body=body)
 
     assert response.text == text
 
@@ -293,7 +293,7 @@ def test_http_headers_declared_encoding(headers, encoding):
     headers = HttpResponseHeaders(headers)
     assert headers.declared_encoding() == encoding
 
-    response = HttpResponse("http://example.com", b'', headers=headers)
+    response = HttpResponse("http://example.com", body=b'', headers=headers)
     assert response.encoding == encoding or HttpResponse._DEFAULT_ENCODING
 
 
@@ -307,14 +307,14 @@ def test_http_response_utf16():
 
 
 def test_explicit_encoding():
-    response = HttpResponse("http://www.example.com", "£".encode('utf-8'),
+    response = HttpResponse("http://www.example.com", body="£".encode('utf-8'),
                             encoding='utf-8')
     assert response.encoding == "utf-8"
     assert response.text == "£"
 
 
 def test_explicit_encoding_invalid():
-    response = HttpResponse("http://www.example.com", "£".encode('utf-8'),
+    response = HttpResponse("http://www.example.com", body="£".encode('utf-8'),
                             encoding='latin1')
     assert response.encoding == "latin1"
     assert response.text == "£".encode('utf-8').decode("latin1")
diff --git a/tests/test_requests.py b/tests/test_requests.py
index c13b21c2..ab1ed5fc 100644
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -19,7 +19,7 @@ def async_mock():
     """Workaround since python 3.7 doesn't ship with asyncmock."""
 
     async def async_test(req):
-        return HttpResponse(req.url, b"")
+        return HttpResponse(req.url, body=b"")
 
     mock.MagicMock.__await__ = lambda x: async_test().__await__()
 
diff --git a/web_poet/page_inputs.py b/web_poet/page_inputs.py
index a0ce562e..870d0a02 100644
--- a/web_poet/page_inputs.py
+++ b/web_poet/page_inputs.py
@@ -157,12 +157,12 @@ class HttpRequest:
     """
 
     url: str = attrs.field()
-    method: str = attrs.field(default="GET")
+    method: str = attrs.field(default="GET", kw_only=True)
     headers: HttpRequestHeaders = attrs.field(
-        factory=HttpRequestHeaders, converter=HttpRequestHeaders
+        factory=HttpRequestHeaders, converter=HttpRequestHeaders, kw_only=True
     )
     body: HttpRequestBody = attrs.field(
-        factory=HttpRequestBody, converter=HttpRequestBody
+        factory=HttpRequestBody, converter=HttpRequestBody, kw_only=True
     )
 
 
@@ -190,11 +190,12 @@ class HttpResponse:
     """
 
     url: str = attrs.field()
-    body: HttpResponseBody = attrs.field(converter=HttpResponseBody)
-    status: Optional[int] = attrs.field(default=None)
+    body: HttpResponseBody = attrs.field(converter=HttpResponseBody, kw_only=True)
+    status: Optional[int] = attrs.field(default=None, kw_only=True)
     headers: HttpResponseHeaders = attrs.field(factory=HttpResponseHeaders,
-                                               converter=HttpResponseHeaders)
-    _encoding: Optional[str] = attrs.field(default=None)
+                                               converter=HttpResponseHeaders,
+                                               kw_only=True)
+    _encoding: Optional[str] = attrs.field(default=None, kw_only=True)
 
     _DEFAULT_ENCODING = 'ascii'
     _cached_text: Optional[str] = None