diff --git a/tools/wptserve/tests/functional/base.py b/tools/wptserve/tests/functional/base.py
index 741ab0bcb74575..f8331f5086d317 100644
--- a/tools/wptserve/tests/functional/base.py
+++ b/tools/wptserve/tests/functional/base.py
@@ -75,7 +75,7 @@ def request(self, path, query=None, method="GET", headers=None, body=None, auth=
             req.add_data(body)
 
         if auth is not None:
-            req.add_header("Authorization", b"Basic %s" % base64.b64encode(("%s:%s" % auth).encode("utf-8")))
+            req.add_header("Authorization", b"Basic %s" % base64.b64encode((b"%s:%s" % auth)))
 
         return urlopen(req)
 
diff --git a/tools/wptserve/tests/functional/test_pipes.py b/tools/wptserve/tests/functional/test_pipes.py
index 7739af5e26e17c..fdac4537d64fb5 100644
--- a/tools/wptserve/tests/functional/test_pipes.py
+++ b/tools/wptserve/tests/functional/test_pipes.py
@@ -115,7 +115,6 @@ def test_sub_uuid(self):
     def test_sub_var(self):
         resp = self.request("/sub_var.sub.txt")
         port = self.server.port
-        print(port, type(port))
         expected = b"localhost %d A %d B localhost C" % (port, port)
         self.assertEqual(resp.read().rstrip(), expected)
 
diff --git a/tools/wptserve/tests/functional/test_request.py b/tools/wptserve/tests/functional/test_request.py
index 3063a0311810b0..276fab1a060334 100644
--- a/tools/wptserve/tests/functional/test_request.py
+++ b/tools/wptserve/tests/functional/test_request.py
@@ -142,6 +142,12 @@ def handler(request, response):
 
         route = ("GET", "/test/test_auth", handler)
         self.server.router.register(*route)
-        resp = self.request(route[1], auth=("test", "PASS"))
+
+        resp = self.request(route[1], auth=(b"test", b"PASS"))
         self.assertEqual(200, resp.getcode())
         self.assertEqual([b"test", b"PASS"], resp.read().split(b" "))
+
+        encoded_text = u"どうも".encode("shift-jis")
+        resp = self.request(route[1], auth=(encoded_text, encoded_text))
+        self.assertEqual(200, resp.getcode())
+        self.assertEqual([encoded_text, encoded_text], resp.read().split(b" "))
diff --git a/tools/wptserve/wptserve/pipes.py b/tools/wptserve/wptserve/pipes.py
index 737b14d11cff82..102cafb30866cb 100644
--- a/tools/wptserve/wptserve/pipes.py
+++ b/tools/wptserve/wptserve/pipes.py
@@ -489,8 +489,9 @@ def config_replacement(match):
         escape_func = {"html": lambda x:escape(x, quote=True),
                        "none": lambda x:x}[escape_type]
 
-        #Should possibly support escaping for other contexts e.g. script
-        #TODO: read the encoding of the response
+        # Should possibly support escaping for other contexts e.g. script
+        # TODO: read the encoding of the response
+        # cgi.escape() only takes text strings in Python 3.
         if isinstance(value, binary_type):
             value = value.decode("utf-8")
         elif isinstance(value, int):
diff --git a/tools/wptserve/wptserve/request.py b/tools/wptserve/wptserve/request.py
index bcd39dd5b9c9f2..990774cbb9e6a1 100644
--- a/tools/wptserve/wptserve/request.py
+++ b/tools/wptserve/wptserve/request.py
@@ -377,8 +377,8 @@ class RequestHeaders(dict):
     """Read-only dictionary-like API for accessing request headers.
 
     Unlike BaseHTTPRequestHandler.headers, this class always returns all
-    headers with the same name (separated by commas). Besides, this class
-    ensures all keys (i.e. names of headers) and values have binary type.
+    headers with the same name (separated by commas). And it ensures all keys
+    (i.e. names of headers) and values have binary type.
     """
     def __init__(self, items):
         for header in items.keys():