diff --git a/drivers/net/wireless/intel/iwlegacy/4965-mac.c b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
index 3588dec75ebd..57fa866efd9f 100644
--- a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
@@ -4606,7 +4606,9 @@ il4965_store_tx_power(struct device *d, struct device_attribute *attr,
 	if (ret)
 		IL_INFO("%s is not in decimal form.\n", buf);
 	else {
+		mutex_lock(&il->mutex);
 		ret = il_set_tx_power(il, val, false);
+		mutex_unlock(&il->mutex);
 		if (ret)
 			IL_ERR("failed setting tx power (0x%08x).\n", ret);
 		else