diff --git a/reactos/drivers/input/kbdclass/kbdclass.c b/reactos/drivers/input/kbdclass/kbdclass.c
index 8b678990fea..8800b61046a 100644
--- a/reactos/drivers/input/kbdclass/kbdclass.c
+++ b/reactos/drivers/input/kbdclass/kbdclass.c
@@ -695,7 +695,7 @@ ClassAddDevice(
 	}
 
 	DeviceExtension = (PPORT_DEVICE_EXTENSION)Fdo->DeviceExtension;
-	RtlZeroMemory(DeviceExtension, sizeof(CLASS_DEVICE_EXTENSION));
+	RtlZeroMemory(DeviceExtension, sizeof(PPORT_DEVICE_EXTENSION));
 	DeviceExtension->Common.IsClassDO = FALSE;
 	DeviceExtension->DeviceObject = Fdo;
 	DeviceExtension->PnpState = dsStopped;