diff --git a/src/calibre/srv/tests/auth.py b/src/calibre/srv/tests/auth.py
index 231a600b26..adfa0aa88a 100644
--- a/src/calibre/srv/tests/auth.py
+++ b/src/calibre/srv/tests/auth.py
@@ -100,7 +100,7 @@ class TestAuth(BaseTest):
             conn.request('GET', '/closed')
             r = conn.getresponse()
             self.ae(r.status, http_client.UNAUTHORIZED)
-            self.ae(r.getheader('WWW-Authenticate'), b'Basic realm="%s"' % bytes(REALM))
+            self.ae(r.getheader('WWW-Authenticate'), 'Basic realm="%s"' % REALM)
             self.assertFalse(r.read())
             conn.request('GET', '/closed', headers={'Authorization': b'Basic ' + as_base64_bytes(b'testuser:testpw')})
             r = conn.getresponse()
@@ -180,11 +180,13 @@ class TestAuth(BaseTest):
                 return {normalize_header_name(k):v for k, v in r.getheaders()}
             conn = server.connect()
             test(conn, '/open', body=b'open')
-            auth = parse_http_dict(test(conn, '/closed', status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(b' ')[2])
+            auth = parse_http_dict(test(conn, '/closed', status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(' ')[2])
             nonce = auth['nonce']
-            auth = parse_http_dict(test(conn, '/closed', status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(b' ')[2])
+            auth = parse_http_dict(test(conn, '/closed', status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(' ')[2])
             self.assertNotEqual(nonce, auth['nonce'], 'nonce was re-used')
-            self.ae(auth[b'realm'], bytes(REALM)), self.ae(auth[b'algorithm'], b'MD5'), self.ae(auth[b'qop'], b'auth')
+            self.ae(auth['realm'], REALM)
+            self.ae(auth['algorithm'], 'MD5')
+            self.ae(auth['qop'], 'auth')
             self.assertNotIn('stale', auth)
             args = auth.copy()
             args['un'], args['pw'], args['uri'] = 'testuser', 'testpw', '/closed'
@@ -202,7 +204,7 @@ class TestAuth(BaseTest):
             # Check stale nonces
             orig, r.auth_controller.max_age_seconds = r.auth_controller.max_age_seconds, -1
             auth = parse_http_dict(test(conn, '/closed', headers={
-                'Authorization':digest(**args)},status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(b' ')[2])
+                'Authorization':digest(**args)},status=http_client.UNAUTHORIZED)['WWW-Authenticate'].partition(' ')[2])
             self.assertIn('stale', auth)
             r.auth_controller.max_age_seconds = orig
             ok_test(conn, digest(**args))
diff --git a/src/calibre/srv/tests/http.py b/src/calibre/srv/tests/http.py
index a434990ef4..87836d22d6 100644
--- a/src/calibre/srv/tests/http.py
+++ b/src/calibre/srv/tests/http.py
@@ -34,20 +34,20 @@ class TestHTTP(BaseTest):
             self.assertSetEqual(set(p.hdict.items()), {(k.replace('_', '-').title(), v) for k, v in iteritems(kwargs)}, name + ' failed')
 
         test('Continuation line parsing',
-             'a: one',
-             'b: two',
-             ' 2',
-             '\t3',
-             'c:three',
-             '\r\n', a='one', b='two 2 3', c='three')
+             b'a: one',
+             b'b: two',
+             b' 2',
+             b'\t3',
+             b'c:three',
+             b'\r\n', a='one', b='two 2 3', c='three')
 
         test('Non-ascii headers parsing',
-             'a:mūs\r'.encode('utf-8'), '\r\n', a='mūs')
+             'a:mūs\r'.encode('utf-8'), b'\r\n', a='mūs')
 
         test('Comma-separated parsing',
-             'Accept-Encoding: one',
-             'accept-Encoding: two',
-             '\r\n', accept_encoding='one, two')
+             b'Accept-Encoding: one',
+             b'accept-Encoding: two',
+             b'\r\n', accept_encoding='one, two')
 
         def parse(*lines):
             lines = list(lines)
@@ -98,7 +98,7 @@ class TestHTTP(BaseTest):
                 r = conn.getresponse()
                 self.ae(r.status, http_client.OK)
                 q += getattr(get_translator(q)[-1], 'gettext' if ispy3 else 'ugettext')('Unknown')
-                self.ae(r.read(), q)
+                self.ae(r.read(), q.encode('utf-8'))
 
             test('en', 'en')
             test('eng', 'en')
@@ -317,7 +317,7 @@ class TestHTTP(BaseTest):
             return conn.generate_static_output('test', lambda : ''.join(conn.path))
         with NamedTemporaryFile(suffix='test.epub') as f, open(P('localization/locales.zip'), 'rb') as lf, \
                 TestServer(handler, timeout=1, compress_min_size=0) as server:
-            fdata = string.ascii_letters * 100
+            fdata = (string.ascii_letters * 100).encode('ascii')
             f.write(fdata), f.seek(0)
 
             # Test ETag
@@ -326,7 +326,7 @@ class TestHTTP(BaseTest):
             r = conn.getresponse()
             self.ae(r.status, http_client.OK), self.ae(r.read(), b'an_etagged_path')
             etag = r.getheader('ETag')
-            self.ae(etag, '"%s"' % hashlib.sha1('an_etagged_path').hexdigest())
+            self.ae(etag, '"%s"' % hashlib.sha1(b'an_etagged_path').hexdigest())
             conn.request('GET', '/an_etagged_path', headers={'If-None-Match':etag})
             r = conn.getresponse()
             self.ae(r.status, http_client.NOT_MODIFIED)
@@ -353,7 +353,7 @@ class TestHTTP(BaseTest):
             r = conn.getresponse()
             self.ae(r.status, http_client.OK), self.ae(r.read(), b'data')
             etag = r.getheader('ETag')
-            self.ae(etag, b'"xxx"')
+            self.ae(etag, '"xxx"')
             self.ae(r.getheader('Content-Length'), '4')
             conn.request('GET', '/an_etagged_path', headers={'If-None-Match':etag})
             r = conn.getresponse()