diff --git a/applications/drv_ec800k.c b/applications/drv_ec800k.c
index b03c987..2a867e0 100644
--- a/applications/drv_ec800k.c
+++ b/applications/drv_ec800k.c
@@ -205,8 +205,8 @@ int16_t BSP_LTE_GetCGATT(int16_t retry) {
 //   return ret;
 // }
 
-int BSP_LTE_GetCSQ(void) {
-  int ret = -1;
+int8_t BSP_LTE_GetCSQ(void) {
+  int8_t ret = 0;
   char *start;
 
   if (0 != BSP_LTE_SendCmd(AT_CSQ, DEFAULT_EXPECT, DEFAULT_ERROR,
@@ -221,7 +221,6 @@ int BSP_LTE_GetCSQ(void) {
 
   start += rt_strlen(CSQ_CMD_RESP) + 1;
 
-  ret = 0;
   while (*start >= '0' && *start <= '9') {
     ret = ret * 10 + (*start - '0');
     start++;
diff --git a/applications/drv_ec800k.h b/applications/drv_ec800k.h
index fedbf9a..e4eac20 100644
--- a/applications/drv_ec800k.h
+++ b/applications/drv_ec800k.h
@@ -281,7 +281,7 @@ void BSP_LTE_GetICCID(char *pICCID);
 int16_t BSP_LTE_GetBsInfo(int *lte_mcc, int *lte_mnc, int *lte_lac,
                           int *lte_cellid);
 
-int BSP_LTE_GetCSQ(void);
+int8_t BSP_LTE_GetCSQ(void);
 
 uint32_t BSP_LTE_GetTimeMs(void);