diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index 923bdbc..a710bdd 100644
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -41,6 +41,7 @@
 
 void ps2_init(struct ps2dev *ps2dev, struct serio *serio);
 int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout);
+void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout);
 int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data);