diff --git a/bitcoinlib/services/services.py b/bitcoinlib/services/services.py
index 82d96d4f..48b6cc79 100644
--- a/bitcoinlib/services/services.py
+++ b/bitcoinlib/services/services.py
@@ -374,7 +374,7 @@ def gettransactions(self, address, after_txid='', limit=MAX_TRANSACTIONS):
             if txs is False:
                 raise ServiceError("Error when retrieving transactions from service provider")
             for tx in txs:
-                if not tx.date.tzinfo:
+                if tx.date and not tx.date.tzinfo:
                     tx.date = tx.date.replace(tzinfo=timezone.utc)
 
         # Store transactions and address in cache