diff --git a/Assets/Scripts/UVC/UI/Menu/TopMenuView.cs b/Assets/Scripts/UVC/UI/Menu/TopMenuView.cs
index 73f975c0..3cc89ff1 100644
--- a/Assets/Scripts/UVC/UI/Menu/TopMenuView.cs
+++ b/Assets/Scripts/UVC/UI/Menu/TopMenuView.cs
@@ -208,12 +208,15 @@ namespace UVC.UI.Menu
                 // CreateUIBlocker 호출 시점에는 menuContainer의 sibling index가 확정되지 않았을 수 있으므로,
                 // UpdateBlockerVisibility에서 최종적으로 조정하는 것이 더 안전할 수 있습니다.
                 // 여기서는 일단 menuContainer의 뒤에 두도록 시도합니다.
-                uiBlockerInstance.transform.SetSiblingIndex(menuContainer.GetSiblingIndex() - 1);
+                // 여기서는 일단 menuContainer의 뒤에 두도록 시도합니다.
+                int siblingIndex = menuContainer.GetSiblingIndex();
+                uiBlockerInstance.transform.SetSiblingIndex(Math.Max(0, siblingIndex - 1));
             }
             else if (transform.parent == blockerParent)
             {
                 // TopMenuView 자체가 blockerParent의 자식인 경우, TopMenuView 뒤에 블로커를 둡니다.
-                uiBlockerInstance.transform.SetSiblingIndex(transform.GetSiblingIndex() - 1);
+                int siblingIndex = transform.GetSiblingIndex();
+                uiBlockerInstance.transform.SetSiblingIndex(Math.Max(0, siblingIndex - 1));
             }
             else
             {
@@ -615,11 +618,13 @@ namespace UVC.UI.Menu
                     Transform blockerParent = uiBlockerInstance.transform.parent;
                     if (menuContainer != null && menuContainer.parent == blockerParent)
                     {
-                        uiBlockerInstance.transform.SetSiblingIndex(menuContainer.GetSiblingIndex() - 1);
+                        int siblingIndex = menuContainer.GetSiblingIndex();
+                        uiBlockerInstance.transform.SetSiblingIndex(Math.Max(0, siblingIndex - 1));
                     }
                     else if (transform.parent == blockerParent)
                     {
-                        uiBlockerInstance.transform.SetSiblingIndex(transform.GetSiblingIndex() - 1);
+                        int siblingIndex = transform.GetSiblingIndex();
+                        uiBlockerInstance.transform.SetSiblingIndex(Math.Max(0, siblingIndex - 1));
                     }
                     else
                     {