diff --git a/reactos/ntoskrnl/io/pnpmgr/pnpmgr.c b/reactos/ntoskrnl/io/pnpmgr/pnpmgr.c
index 57129dd0b60..29842a5ca87 100644
--- a/reactos/ntoskrnl/io/pnpmgr/pnpmgr.c
+++ b/reactos/ntoskrnl/io/pnpmgr/pnpmgr.c
@@ -1270,6 +1270,7 @@ IopAssignDeviceResources(
    {
       /* No resource needed for this device */
       DeviceNode->ResourceList = NULL;
+      *pRequiredSize = 0;
       return STATUS_SUCCESS;
    }