diff --git a/src/libraries/System.Linq/src/System/Linq/OrderedEnumerable.SpeedOpt.cs b/src/libraries/System.Linq/src/System/Linq/OrderedEnumerable.SpeedOpt.cs
index e69eb734ea142..bf65a34b06efa 100644
--- a/src/libraries/System.Linq/src/System/Linq/OrderedEnumerable.SpeedOpt.cs
+++ b/src/libraries/System.Linq/src/System/Linq/OrderedEnumerable.SpeedOpt.cs
@@ -479,7 +479,7 @@ public override bool MoveNext()
                 }
                 else if (state == 1)
                 {
-                    TElement[] buffer = _source.ToArray();
+                    TElement[] buffer = _source._source.ToArray();
                     int count = buffer.Length;
                     if (count > _minIndexInclusive)
                     {