diff --git a/alpaca_trade_api/polygon/streamconn.py b/alpaca_trade_api/polygon/streamconn.py
index 0068ae6f..e14dad85 100644
--- a/alpaca_trade_api/polygon/streamconn.py
+++ b/alpaca_trade_api/polygon/streamconn.py
@@ -124,7 +124,7 @@ async def _ensure_ws(self):
             try:
                 await self.connect()
                 if self._streams:
-                    await self.subscribe(self._streams)
+                    await self.subscribe(list(self._streams))
                 break
             except Exception as e:
                 await self._dispatch({'ev': 'status',
diff --git a/alpaca_trade_api/stream2.py b/alpaca_trade_api/stream2.py
index a0c39e04..f2825873 100644
--- a/alpaca_trade_api/stream2.py
+++ b/alpaca_trade_api/stream2.py
@@ -99,7 +99,7 @@ async def _ensure_ws(self):
             try:
                 await self._connect()
                 if self._streams:
-                    await self.subscribe(self._streams)
+                    await self.subscribe(list(self._streams))
                 break
             except websockets.WebSocketException as wse:
                 logging.warn(wse)