diff --git a/SDK/INC/NT/ntdef.h b/SDK/INC/NT/ntdef.h
index 5534ddc..25e70c8 100644
--- a/SDK/INC/NT/ntdef.h
+++ b/SDK/INC/NT/ntdef.h
@@ -260,6 +260,66 @@ Return Value:
     Head->Flink = Head;
 }
 
+FORCEINLINE
+VOID
+InsertHeadList (
+    IN PLIST_ENTRY Head,
+    IN PLIST_ENTRY Entry
+    )
+
+/*++
+
+Routine Description:
+
+    Inserts a list entry at the head of a list.
+
+Arguments:
+
+    Entry - The list entry.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+    Entry->Flink = Head->Flink;
+    Entry->Blink = Head;
+    Head->Flink->Blink = Entry;
+    Head->Flink = Entry;
+}
+
+FORCEINLINE
+VOID
+InsertTailList (
+    IN PLIST_ENTRY Head,
+    IN PLIST_ENTRY Entry
+    )
+
+/*++
+
+Routine Description:
+
+    Inserts a list entry at the tail of a list.
+
+Arguments:
+
+    Entry - The list entry.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+    Entry->Blink = Head->Blink;
+    Entry->Flink = Head;
+    Head->Blink->Flink = Entry;
+    Head->Blink = Entry;
+}
+
 FORCEINLINE
 BOOLEAN
 RemoveEntryList (