diff --git a/tests/fixtures/news.yaml b/tests/fixtures/news.yaml
index e1d6464..a18c772 100644
--- a/tests/fixtures/news.yaml
+++ b/tests/fixtures/news.yaml
@@ -9,7 +9,7 @@ interactions:
       Content-Type: [application/json]
       User-Agent: [tiingo-python-client 0.3.2]
     method: GET
-    uri: https://api.tiingo.com/tiingo/news?limit=1&offset=0&sortBy=publishedDate&tickers=aapl&tickers=googl&sources=washingtonpost.com&sources=altcointoday.com&tags=Technology&tags=Bitcoin&startDate=2016-01-01&endDate=2017-08-31
+    uri: https://api.tiingo.com/tiingo/news?limit=1&offset=0&sortBy=publishedDate&tickers=aapl&tickers=googl&source=cnbc.com,altcointoday.com&tags=Technology&tags=Bitcoin&startDate=2016-01-01&endDate=2017-08-31
   response:
     body: {string: '[{
     "publishedDate": "2016-01-11T23:13:00Z",
diff --git a/tests/test_tiingo.py b/tests/test_tiingo.py
index 9d920c2..c92997a 100644
--- a/tests/test_tiingo.py
+++ b/tests/test_tiingo.py
@@ -155,7 +155,7 @@ class TestNews(TestCase):
             "tags": ["Technology", "Bitcoin"],
             "startDate": "2016-01-01",
             "endDate": "2017-08-31",
-            "sources": ['washingtonpost.com', 'altcointoday.com'],
+            "sources": ['cnbc.com', 'altcointoday.com'],
             "limit": self.num_articles
         }
 
diff --git a/tiingo/api.py b/tiingo/api.py
index b8b3467..0cf9fbb 100644
--- a/tiingo/api.py
+++ b/tiingo/api.py
@@ -299,7 +299,7 @@ class TiingoClient(RestClient):
             'offset': offset,
             'sortBy': sortBy,
             'tickers': tickers,
-            'sources': sources,
+            'source': (",").join(sources),
             'tags': tags,
             'startDate': startDate,
             'endDate': endDate