diff --git a/src/pycoornet/crowdtangle.py b/src/pycoornet/crowdtangle.py
index 08746b7..31796c5 100644
--- a/src/pycoornet/crowdtangle.py
+++ b/src/pycoornet/crowdtangle.py
@@ -90,7 +90,7 @@ def get_shares(self, urls, url_column='url', date_column='date', platforms=('fac
                     days = f"{remove_days} day"
                     endDate = startDate + pd.Timedelta(days)
                 else:
-                    endDate = 'now'
+                    endDate = None
 
                 url = urls.iloc[i, :].loc['url']
                 try: