diff --git a/QuantConnect.Polygon.Tests/PolygonHistoryTests.cs b/QuantConnect.Polygon.Tests/PolygonHistoryTests.cs
index 2928c78..ca555ef 100644
--- a/QuantConnect.Polygon.Tests/PolygonHistoryTests.cs
+++ b/QuantConnect.Polygon.Tests/PolygonHistoryTests.cs
@@ -208,7 +208,6 @@ public void GetsSameBarCountForDifferentResponseLimits()
             new TestCaseData(Symbols.USDJPY, Resolution.Minute, TickType.Trade),
             new TestCaseData(Symbols.BTCUSD, Resolution.Minute, TickType.Trade),
             new TestCaseData(Symbols.DE10YBEUR, Resolution.Minute, TickType.Trade),
-            new TestCaseData(Symbols.SPX, Resolution.Minute, TickType.Trade),
             new TestCaseData(Symbols.Future_ESZ18_Dec2018, Resolution.Minute, TickType.Trade),
 
             // Supported security type and resolution, unsupported tick type
diff --git a/QuantConnect.Polygon/PolygonOptionChainProvider.cs b/QuantConnect.Polygon/PolygonOptionChainProvider.cs
index 1bb221b..7778851 100644
--- a/QuantConnect.Polygon/PolygonOptionChainProvider.cs
+++ b/QuantConnect.Polygon/PolygonOptionChainProvider.cs
@@ -65,11 +65,10 @@ public IEnumerable<Symbol> GetOptionContractList(Symbol symbol, DateTime date)
             }
 
             var underlying = symbol.SecurityType.IsOption() ? symbol.Underlying : symbol;
-            var brokerageSymbol = _symbolMapper.GetBrokerageSymbol(underlying);
             var optionsSecurityType = underlying.SecurityType == SecurityType.Index ? SecurityType.IndexOption : SecurityType.Option;
 
             var request = new RestRequest("/v3/reference/options/contracts", Method.GET);
-            request.AddQueryParameter("underlying_ticker", brokerageSymbol);
+            request.AddQueryParameter("underlying_ticker", underlying.ID.Symbol);
             request.AddQueryParameter("as_of", date.ToStringInvariant("yyyy-MM-dd"));
             request.AddQueryParameter("limit", "1000");