diff --git a/src/Microsoft.OpenApi.OData.Reader/Operation/DollarCountGetOperationHandler.cs b/src/Microsoft.OpenApi.OData.Reader/Operation/DollarCountGetOperationHandler.cs
index fdf1082..9cfcb74 100644
--- a/src/Microsoft.OpenApi.OData.Reader/Operation/DollarCountGetOperationHandler.cs
+++ b/src/Microsoft.OpenApi.OData.Reader/Operation/DollarCountGetOperationHandler.cs
@@ -25,7 +25,7 @@ namespace Microsoft.OpenApi.OData.Operation
         /// this segment could be "entity set", "Collection property", "Composable function whose return is collection",etc.
         /// </summary>
         internal ODataSegment LastSecondSegment { get; set; }
-
+        private const int SecondLastSegmentIndex = 2;
         /// <inheritdoc/>
         protected override void Initialize(ODataContext context, ODataPath path)
         {
@@ -33,7 +33,8 @@ namespace Microsoft.OpenApi.OData.Operation
 
             // get the last second segment
             int count = path.Segments.Count;
-            LastSecondSegment = path.Segments.ElementAt(count - 1);
+            if(count >= SecondLastSegmentIndex)
+                LastSecondSegment = path.Segments.ElementAt(count - SecondLastSegmentIndex);
         }
 
         /// <inheritdoc/>