diff --git a/drivers/input/touchscreen/cyttsp_core.c b/drivers/input/touchscreen/cyttsp_core.c
index 8e60437ac85b..97ba89128312 100644
--- a/drivers/input/touchscreen/cyttsp_core.c
+++ b/drivers/input/touchscreen/cyttsp_core.c
@@ -133,7 +133,7 @@ static int cyttsp_exit_bl_mode(struct cyttsp *ts)
 	memcpy(bl_cmd, bl_command, sizeof(bl_command));
 	if (ts->pdata->bl_keys)
 		memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
-			ts->pdata->bl_keys, sizeof(bl_command));
+			ts->pdata->bl_keys, CY_NUM_BL_KEYS);
 
 	error = ttsp_write_block_data(ts, CY_REG_BASE,
 				      sizeof(bl_cmd), bl_cmd);