diff --git a/src/dotnet/APIView/APIViewWeb/Helpers/CodeFileHelpers.cs b/src/dotnet/APIView/APIViewWeb/Helpers/CodeFileHelpers.cs
index ce436d016b1..7a9ee3e5e18 100644
--- a/src/dotnet/APIView/APIViewWeb/Helpers/CodeFileHelpers.cs
+++ b/src/dotnet/APIView/APIViewWeb/Helpers/CodeFileHelpers.cs
@@ -738,12 +738,12 @@ private static void InsertCodePanelRowData(CodePanelData codePanelData, CodePane
                 commentsForRow.AssociatedRowPositionInGroup = rowData.RowPositionInGroup;
                 if (codePanelData.NodeMetaDataObj.ContainsKey(nodeIdHashed))
                 {
-                    codePanelData.NodeMetaDataObj[nodeIdHashed].CommentThreadObj.Add(codePanelData.NodeMetaDataObj[nodeIdHashed].CodeLinesObj.Count() - 1, commentsForRow); //Map comment to the index of associated codeLine
+                    codePanelData.NodeMetaDataObj[nodeIdHashed].CommentThreadObj.TryAdd(codePanelData.NodeMetaDataObj[nodeIdHashed].CodeLinesObj.Count() - 1, commentsForRow); //Map comment to the index of associated codeLine
                 }
                 else
                 {
                     codePanelData.NodeMetaDataObj.TryAdd(nodeIdHashed, new CodePanelNodeMetaData());
-                    codePanelData.NodeMetaDataObj[nodeIdHashed].CommentThreadObj.Add(codePanelData.NodeMetaDataObj[nodeIdHashed].CodeLinesObj.Count() - 1, commentsForRow); //Map comment to the index of associated codeLine
+                    codePanelData.NodeMetaDataObj[nodeIdHashed].CommentThreadObj.TryAdd(codePanelData.NodeMetaDataObj[nodeIdHashed].CodeLinesObj.Count() - 1, commentsForRow); //Map comment to the index of associated codeLine
                 }
             }
         }
diff --git a/src/dotnet/APIView/APIViewWeb/LeanModels/ReviewRevisionPageModels.cs b/src/dotnet/APIView/APIViewWeb/LeanModels/ReviewRevisionPageModels.cs
index b84cfcb8e49..9009ae37d98 100644
--- a/src/dotnet/APIView/APIViewWeb/LeanModels/ReviewRevisionPageModels.cs
+++ b/src/dotnet/APIView/APIViewWeb/LeanModels/ReviewRevisionPageModels.cs
@@ -111,8 +111,8 @@ public class CodePanelNodeMetaData
         public List<CodePanelRowData> CodeLinesObj { get; set; } = new List<CodePanelRowData>();
         public List<CodePanelRowData> CodeLines => CodeLinesObj.Count > 0 ? CodeLinesObj : null;
         [JsonIgnore]
-        public Dictionary<int, CodePanelRowData> CommentThreadObj { get; set; } = new Dictionary<int, CodePanelRowData>(); //Dictionary key map to the index of the code line within this node which the comment thread is mapped to
-        public Dictionary<int, CodePanelRowData> CommentThread => CommentThreadObj.Count > 0 ? CommentThreadObj : null;
+        public ConcurrentDictionary<int, CodePanelRowData> CommentThreadObj { get; set; } = new ConcurrentDictionary<int, CodePanelRowData>(); //Dictionary key map to the index of the code line within this node which the comment thread is mapped to
+        public ConcurrentDictionary<int, CodePanelRowData> CommentThread => CommentThreadObj.Count > 0 ? CommentThreadObj : null;
         public NavigationTreeNode NavigationTreeNode { get; set; }
         public string ParentNodeIdHashed { get; set; }
         [JsonIgnore]