diff --git a/reactos/drivers/video/videoprt/services.c b/reactos/drivers/video/videoprt/services.c
index 5b9f3cf5036..18862955b67 100644
--- a/reactos/drivers/video/videoprt/services.c
+++ b/reactos/drivers/video/videoprt/services.c
@@ -111,6 +111,6 @@ VideoPortGetAgpServices(
       return FALSE;
    }
 
-   RtlCopyMemory(AgpServices, &Interface.AgpReservePhysical, sizeof(AgpServices));
+   RtlCopyMemory(AgpServices, &Interface.AgpReservePhysical, sizeof(PVIDEO_PORT_AGP_SERVICES));
    return TRUE;
 }