diff --git a/.travis.yml b/.travis.yml
index d8c61e29..0b147e1e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,10 @@ matrix:
       env: TOXENV=py35
     - python: 3.6
       env: TOXENV=py36
+    - python: 3.7
+      env: TOXENV=py37
+      dist: xenial
+      sudo: true
 
 # command to install dependencies
 install:
diff --git a/extruct/_extruct.py b/extruct/_extruct.py
index 1e76bb64..c2323abf 100644
--- a/extruct/_extruct.py
+++ b/extruct/_extruct.py
@@ -39,7 +39,7 @@ def extract(htmlstring, base_url=None, encoding="UTF-8",
        schema_context: schema's context for current page"""
     if base_url is None and 'url' in kwargs:
         warnings.warn('"url" argument is deprecated, please use "base_url"',
-                      DeprecationWarning)
+                      DeprecationWarning, stacklevel=2)
         base_url = kwargs.pop('url')
     if kwargs:
         raise TypeError('Unexpected keyword arguments')
diff --git a/extruct/jsonld.py b/extruct/jsonld.py
index 706b061b..f11580eb 100644
--- a/extruct/jsonld.py
+++ b/extruct/jsonld.py
@@ -10,7 +10,7 @@
 
 from extruct.utils import parse_html
 
-HTML_OR_JS_COMMENTLINE = re.compile('^\s*(//.*|<!--.*-->)')
+HTML_OR_JS_COMMENTLINE = re.compile(r'^\s*(//.*|<!--.*-->)')
 
 
 class JsonLdExtractor(object):
diff --git a/extruct/tool.py b/extruct/tool.py
index ce05368e..8e8f70fa 100644
--- a/extruct/tool.py
+++ b/extruct/tool.py
@@ -14,8 +14,8 @@ def metadata_from_url(url, syntaxes=SYNTAXES, uniform=False,
         resp.raise_for_status()
     except requests.exceptions.HTTPError:
         return result
-    result.update(extruct.extract(resp.content, 
-                                  url=url, 
+    result.update(extruct.extract(resp.content,
+                                  base_url=url,  # FIXME: use base url
                                   syntaxes=syntaxes, 
                                   uniform=uniform,
                                   schema_context=schema_context,
diff --git a/setup.py b/setup.py
index e7ea58ce..5bbc7553 100644
--- a/setup.py
+++ b/setup.py
@@ -57,5 +57,6 @@ def get_version():
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
     ],
 )
diff --git a/tests/test_extruct.py b/tests/test_extruct.py
index f6b2a894..07360fdd 100644
--- a/tests/test_extruct.py
+++ b/tests/test_extruct.py
@@ -2,6 +2,8 @@
 import json
 import unittest
 
+import pytest
+
 import extruct
 from tests import get_testdata, jsonize_dict, replace_node_ref_with_node_id
 
@@ -31,8 +33,9 @@ def test_microdata_with_returning_node(self):
 
     def test_deprecated_url(self):
         body, expected = self._microdata_custom_url('product_custom_url.json')
-        data = extruct.extract(body, url='http://some-example.com',
-                               syntaxes=['microdata'])
+        with pytest.warns(DeprecationWarning):
+            data = extruct.extract(body, url='http://some-example.com',
+                                   syntaxes=['microdata'])
         self.assertEqual(data, expected)
 
     def test_extra_kwargs(self):
diff --git a/tox.ini b/tox.ini
index e2bc2898..e5deb3eb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py34, py35, py36
+envlist = py27, py34, py35, py36, py37
 
 [testenv]
 deps =