diff --git a/drivers/media/video/pwc/pwc-ctrl.c b/drivers/media/video/pwc/pwc-ctrl.c
index 50b415e07eda..f7f7e04cf485 100644
--- a/drivers/media/video/pwc/pwc-ctrl.c
+++ b/drivers/media/video/pwc/pwc-ctrl.c
@@ -753,7 +753,7 @@ int pwc_set_shutter_speed(struct pwc_device *pdev, int mode, int value)
 		buf[0] = 0xff; /* fixed */
 
 	ret = send_control_msg(pdev,
-		SET_LUM_CTL, SHUTTER_MODE_FORMATTER, &buf, sizeof(buf));
+		SET_LUM_CTL, SHUTTER_MODE_FORMATTER, &buf, 1);
 
 	if (!mode && ret >= 0) {
 		if (value < 0)