diff --git a/ntoskrnl/include/internal/ex.h b/ntoskrnl/include/internal/ex.h
index 4c212972fcb..3b3a2fbafb9 100644
--- a/ntoskrnl/include/internal/ex.h
+++ b/ntoskrnl/include/internal/ex.h
@@ -1510,6 +1510,20 @@ ExTimerRundown(
     VOID
 );
 
+VOID
+NTAPI
+ExUnlockUserBuffer(PMDL Mdl);
+
+NTSTATUS
+NTAPI
+ExLockUserBuffer(
+    PVOID BaseAddress,
+    ULONG Length,
+    KPROCESSOR_MODE AccessMode,
+    LOCK_OPERATION Operation,
+    PVOID *MappedSystemVa,
+    PMDL *OutMdl);
+
 CODE_SEG("INIT")
 VOID
 NTAPI