diff --git a/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c b/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c
index 1cdf5a271c9f..b793a659a465 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c
@@ -669,7 +669,8 @@ static void rtl92c_dm_txpower_tracking_callback_thermalmeter(struct ieee80211_hw
 	u8 thermalvalue, delta, delta_lck, delta_iqk;
 	long ele_a, ele_d, temp_cck, val_x, value32;
 	long val_y, ele_c = 0;
-	u8 ofdm_index[2], cck_index = 0, ofdm_index_old[2], cck_index_old = 0;
+	u8 ofdm_index[2], ofdm_index_old[2], cck_index_old = 0;
+	s8 cck_index = 0;
 	int i;
 	bool is2t = IS_92C_SERIAL(rtlhal->version);
 	s8 txpwr_level[2] = {0, 0};