diff --git a/reactos/include/psdk/ks.h b/reactos/include/psdk/ks.h
index 416d289c7fc..8a489f14400 100644
--- a/reactos/include/psdk/ks.h
+++ b/reactos/include/psdk/ks.h
@@ -2975,7 +2975,7 @@ KsFreeObjectCreateItemsByContext(
     IN  KSDEVICE_HEADER Header,
     IN  PVOID Context);
 
-VOID
+KSDDKAPI VOID NTAPI
 KsNullDriverUnload(
     IN  PDRIVER_OBJECT DriverObject);