diff --git a/dlls/ntoskrnl.exe/ntoskrnl.c b/dlls/ntoskrnl.exe/ntoskrnl.c
index 35d7db05027..2aac40951cf 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.c
+++ b/dlls/ntoskrnl.exe/ntoskrnl.c
@@ -247,6 +247,15 @@ NTSTATUS wine_ntoskrnl_main_loop( HANDLE stop_event )
     }
 }
 
+/***********************************************************************
+ *           IoAllocateMdl  (NTOSKRNL.EXE.@)
+ */
+PMDL WINAPI IoAllocateMdl( PVOID VirtualAddress, ULONG Length, BOOLEAN SecondaryBuffer, BOOLEAN ChargeQuota, PIRP Irp )
+{
+    FIXME( "stub: %p, %u, %i, %i, %p \n", VirtualAddress, Length, SecondaryBuffer, ChargeQuota, Irp );
+    return NULL;
+}
+
 
 /***********************************************************************
  *           IoAllocateWorkItem  (NTOSKRNL.EXE.@)
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 689d0b3779d..31175094921 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -312,7 +312,7 @@
 @ stub IoAllocateDriverObjectExtension
 @ stub IoAllocateErrorLogEntry
 @ stub IoAllocateIrp
-@ stub IoAllocateMdl
+@ stdcall IoAllocateMdl(ptr long long long ptr)
 @ stdcall IoAllocateWorkItem(ptr)
 @ stub IoAssignResources
 @ stub IoAttachDevice